NCERT Solutions Class 4 Maths Chapter 6 Measuring Length

F R E E S T U D Y M AT E R I A L F O R E V E R Y S T U D E N T

C L A S S 4 · M AT H S

NCERT Solutions

Chapter 6: Measuring Length

NCERT Textbook — Math Mela

BOOK PAGES SECTIONS QUESTIONS MEDIUM

80 – 94 11 49 English

Solutions, notes, sample papers & more at 58 pages

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

CLASS 4 · MATHS · MATH MELA

NCERT Solutions — Chapter 6: Measuring Length
In this chapter we measure length with rope, tape and scale. We meet the centimetre, learn that 1 m = 100
cm, and find the perimeter — the length all around a shape.

TEXTBOOK BOOK PAGES

Math Mela (Class 4) 80 – 94

SECTIONS QUESTIONS

11 49

MEDIUM

English

Let Us Observe — Page 80

Page 1 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

Measuring Length

Q1 ✓
Look at the picture. What are the students measuring? Put a tick mark ( ) if you
find it being measured. a) Length b) Height c) Weight d) Depth e) Breadth f)
Temperature

The picture on page 80: a school health camp in a classroom. A
banner on the wall reads SCHOOL HEALTH PROGRAMME. On the left a
girl stands still on a flat machine that has a cord running from it. In
the middle a doctor and a nurse are checking two children with a
small flat stick. On the right a boy stands straight on a low platform,
with his back against a tall marked strip fixed to the wall, and a
teacher places his hand flat on top of the boy’s head.

What the picture in your book shows.

The picture on page 80: a school health camp in a classroom. A banner on the
wall reads SCHOOL HEALTH PROGRAMME. On the left a girl stands still on a flat
machine that has a cord running from it. In the middle a doctor and a nurse are
checking two children with a small flat stick. On the right a boy stands straight
on a low platform, with his back against a tall marked strip fixed to the wall, and
a teacher places his hand flat on top of the boy’s head.

What the picture in your book shows.

Tick b) Height and c) Weight.

Page 2 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

WHAT TICK WHO IS DOING IT IN THE PICTURE

a) Length ✘ Nobody is measuring a length lying flat

b) Height ✔ The boy standing against the marked strip on the wall

c) Weight ✔ The girl standing on the machine with a cord

d) Depth ✘ Nothing deep, like a well, is being measured

e) Breadth ✘ Nobody is measuring how wide something is

f) Temperature ✘ No thermometer is being used. The doctor is only looking inside the mouth

Why it happens: We tick only what we can actually see being measured in the
picture. Two things are being measured here — how tall the children are, and how
heavy they are.

Tip: Height is a length. Tall, wide, deep and broad are all words for a length. We
choose the word by the way the thing stands.

Page 3 of 58

as e
Class 4 Maths Chapter 6 Measuring Length
a g l AglaSem · NCERT Solutions

co m
m.
What is being used to measure the height? What other tools can be used to
e
Q2

m l as
.co
measure height?

a g
se m
g l a
a The picture on page 80: a school health camp in a classroom. A

co m
banner on the wall reads SCHOOL HEALTH PROGRAMME. On the left a

e m .
girl stands still on a flat machine that has a cord running from it. In ag
g l as
the middle a doctor and a nurse are checking two children with a
a
small flat stick. On the right a boy stands straight on a low platform,

m
with his back against a tall marked strip fixed to the wall, and a
co
m.
teacher places his hand flat on top of the boy’s head.

m as e
.co a g l
se m What the picture in your book shows.

g l a
a
m a s
.co agl

se m
g l a
a
The picture on page 80: a school health camp in a classroom. A banner on the
wall reads SCHOOL HEALTH PROGRAMME. On the left a girl stands still on a flat
co m
m .
m as e
machine that has a cord running from it. In the middle a doctor and a nurse are

.co a g l
checking two children with a small flat stick. On the right a boy stands straight

s e mon a low platform, with his back against a tall marked strip fixed to the wall, and
agla a teacher places his hand flat on top of the boy’s head.

se m
com
What the picture in your book shows.
g l a
m . a
ase
agl
A long measuring scale fixed to the wall is being used. The boy stands straight on a flat
platform with his back to the scale, and the teacher reads the mark at the top of his head.
Other tools we can use to measure height:
co m
m .
m
a measuring tape, like the one a tailor uses;
as e
.co a g l
m a metre scale or a long ruler;
a 1 metre rope that we made ourselves;

l a se
ag
.c
a stick with marks on it, held straight against the wall.

s e m
com a
. agl
Why it happens: Any tool with equal marks on it can measure height. The tool must

a s em stand straight with feet flat on the floor.
be straight, and the child must

agl

co m
m .
m ase
.co


a g l Page 4 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

Check it yourself: Put a mark on the wall at the top of your head. Then measure
from the floor to that mark with a tape. You get the same answer.

Q3 Recall in Grade 3 you studied that lengths are measured in metres. Check and fill in
the blanks whether the following are correct/incorrect for your classroom. a) The
height of most of the students in my grade is more than a metre. _______________

Correct.

1 m = 100 cm

Height of most Grade 4 children = about 120 cm to 140 cm

120 cm is more than 100 cm → more than 1 m

How to check:

1. Stand straight against a wall with your heels touching it.
2. Ask a friend to put a ruler flat on your head and mark the wall.
3. Measure from the floor to the mark with a measuring tape.
4. Compare that number with 100 cm.

Sample answer: Correct. In my class 32 children out of 35 are taller than 1 m.

Why it happens: A metre is only 100 cm, which is about up to the waist of a grown-
up. Most nine-year-olds are already taller than that.

Q4 b) The length of my arm is less than a metre. _______________

Correct.

Length of my arm = about 55 cm

55 cm is less than 100 cm → less than 1 m

How to check: Stretch your arm out straight. Lay the measuring tape from your shoulder to the
tip of your longest finger and read the mark.

Page 5 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

Sample answer: Correct. My arm is 55 cm long, which is a little more than half a metre.

Why it happens: Your whole body is about 130 cm tall, so one arm must be much
shorter than that — about half a metre.

Q5 c) The height of the door of the grade is less than a metre. __________

Incorrect.

Height of the classroom door = about 2 m

2 m = 200 cm, and 200 cm is more than 100 cm

So the door is more than a metre, not less

How to check: Stand your 1 m rope on the floor beside the door. Mark the top of the rope, then
lift the rope and place it again from that mark. The rope fits about two times.
Sample answer: Incorrect. The door of my classroom is about 2 m high.

Why it happens: A grown-up is taller than 1 m and still walks through the door
without bending. So the door must be taller than 1 m.

Q6 d) The breadth of the blackboard is more than a metre.___________

Correct.

Breadth (the side-to-side length) of the blackboard = about 2 m

2 m = 200 cm, which is more than 100 cm → more than 1 m

How to check: Hold the 1 m rope along the bottom edge of the blackboard. Mark where it ends,
then move the rope again from that mark. It fits about two times.
Sample answer: Correct. My blackboard is 2 m broad.

Page 6 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

Why it happens: The whole class has to see the blackboard, so it is made wide —
wider than one metre rope.

Let Us Do — Page 81
Measuring is Fun

Q1 Remember we made, 1 metre (m), half metre (1/2 m), and quarter metre (1/4 m)
ropes. Let us make them again. Do you notice 1 m = 1/2 m + 1/2 m and 1 m = 1/4 m +
1/4 m + 1/4 m + 1/4 m and 1/2 m = 1/4 m + 1/4 m.

How to make the three ropes:

1. Cut a rope exactly as long as a metre scale. This is the 1 m rope.
2. Take a second rope of 1 m. Hold its two ends together and fold it once. Cut at the fold. You
get two equal pieces — each is a 1/2 m rope.
3. Fold one 1/2 m rope once more and cut at the fold. You get two 1/4 m ropes. Do the same
with the other 1/2 m rope. Now you have four 1/4 m ropes.

1m

1/2 m 1/2 m

1/4 m 1/4 m 1/4 m 1/4 m

One metre rope, two half-metre ropes and four quarter-metre ropes, all laid one below the other.

Yes, we notice all three facts:

1 m = 1/2 m + 1/2 m

1 m = 1/4 m + 1/4 m + 1/4 m + 1/4 m

1/2 m = 1/4 m + 1/4 m

Page 7 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

Why it happens: Every time we fold a rope in half and cut, we make two equal
pieces. So two halves make the whole, and two quarters make one half.

Try this: Lay the four 1/4 m ropes end to end. They reach exactly as far as the 1 m
rope.

Q2 Walk, Jump, and Crawl on 1, 5 and 10 m line. Draw lines of 1 m, 5 m, and 10 m on the
floor of the classroom or outside in the playground. How will you make these lines?
Think and share with your friends. Walk, jump, and crawl on the lines.

How to draw the lines:

1. Put the 1 m rope flat on the floor. Draw a chalk line along it. That is the 1 m line.
2. For the 5 m line, mark the end of the rope, then move the rope forward and start from that
mark. Do this 5 times in a straight line.
3. For the 10 m line, keep going the same way until the rope has been placed 10 times.
4. If you have more ropes, join them end to end. Two 1 m ropes together give 2 m at one go.

5m=1m+1m+1m+1m+1m

10 m = 1 m + 1 m + 1 m + 1 m + 1 m + 1 m + 1 m + 1 m + 1 m + 1 m

Now walk on the 1 m line, jump along the 5 m line and crawl along the 10 m line.

Why it happens: We do not have a 10 m rope. So we repeat the 1 m rope and count
how many times we used it. Repeating an equal length is how all measuring works.

Try this: Walk along the 10 m line with normal steps and count your footsteps. Now
you know about how many of your footsteps make 10 m. You can use that to guess
longer distances.

Let Us Do — Page 82

Page 8 of 58

as e
Class 4 Maths Chapter 6 Measuring Length
a g l AglaSem · NCERT Solutions

Measuring is Fun (Long Jump)
co m
e m.
m l as
.co
Long Jump. Each child can participate in a long jump competition. How far have
a g
emfriends jumped? Measure as accurately as possible using a combination of
Q1

a s
your

a gl ropes. Who jumped the longest distance? Fill the following table.
m
.coM ag
NAME OF THE LESS THAN 1 MORE THAN ACTUAL

sem
STUDENT 1M 1M MEASUREMENT

a
agl

co m
em.
m l as
m .co a g
l a se
g
a ANSWER
How to do it:
m a s
e
. c o
m jumps from this line. agl
s
1. Draw a chalk line on the ground. Everyone

a g
2. Mark the place where the jumper'sla heel lands.
3. First guess: is the jump less than 1 m, about 1 m, or more than 1 m? Tick that column.
4. Now measure. Lay the 1 m rope from the chalk line. If the jump is longer, add the 1/2 m or
co m
m .
e
the 1/4 m rope to it.

m l as
.co g
5. Write the measurement, and the longest jump wins.

m a
l a se
This is the table as it is printed in your book:

a g
NAME OF THE LESS THAN 1 1 MORE THAN 1 ACTUAL
se m
STUDENT M
c o m M M MEASUREMENT
g l a
m . a
ase
agl

co m
m .
o m l a se
g
.c answer (your class will have its own names and numbers):
a
m
Sample

a se
agl c
m .
m a s e
e m . co agl
g l as
a

co m
m .
m ase
.co


a g l Page 9 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

NAME OF THE LESS THAN 1 1 MORE THAN 1 ACTUAL
STUDENT M M M MEASUREMENT

Rani ✔ 3/4 m

Bhola ✔ 1 m 25 cm

Mini ✔ 1m

Jagat ✔ 1 m 50 cm

The longest jump is Jagat's, 1 m 50 cm.

Why it happens: We compare the jumps by putting the numbers side by side. 1 m
50 cm is more than 1 m 25 cm, which is more than 1 m, which is more than 3/4 m.

Tip: Use a combination of ropes. 1 m 25 cm is the 1 m rope and one 1/4 m rope
joined end to end.

Q2 Who has jumped the shortest?

Look again at the same table and find the smallest measurement.

NAME OF THE LESS THAN 1 1 MORE THAN 1 ACTUAL
STUDENT M M M MEASUREMENT

Rani ✔ 3/4 m

Bhola ✔ 1 m 25 cm

Mini ✔ 1m

Jagat ✔ 1 m 50 cm

3/4 m = 75 cm

1 m = 100 cm 1 m 25 cm = 125 cm 1 m 50 cm = 150 cm

The smallest number is 75 cm

Sample answer: Rani jumped the shortest, 3/4 m (75 cm).

Page 10 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

Why it happens: To compare lengths we change them all into the same unit. In
centimetres the numbers can be put in order at one glance.

Q3 Estimate how long and broad is your classroom. Measure and check.

How to do it:

1. First estimate. Walk once along the length of the room with normal steps and count them. If
about 2 of your footsteps make 1 m, then 16 steps is about 8 m.
2. Now measure. Lay the 1 m rope along the wall, mark the end, move the rope to the mark,
and keep counting how many times you place it.
3. Do the same along the shorter wall. That is the breadth.
4. Write both numbers and see how close your estimate was.

Sample answer:

MY ESTIMATE ACTUAL MEASUREMENT

Length of my classroom 8m 7 m 50 cm

Breadth of my classroom 6m 6 m 25 cm

Why it happens: An estimate is a careful guess made by comparing with something
we know. Measuring with the rope then tells us the real length.

Tip: A good estimate is not the same as the right answer. It is good if it is close to the
right answer.

Let Us Think: Guess the Length — Page 83

Page 11 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

Measuring is Fun

Q1 What is the length of one bus in metres? What is the length of one cricket bat in
metres?

Length about 30 metres

Length about 6 metres

4m
3m

The pictures on page 83: a blue whale with two buses below it, a giraffe in a barrel, an ostrich and a
crocodile with cricket bats below it.

One bus is about 15 m long. One cricket bat is about 1 m long.

Two buses stand end to end under the 30 m arrow.

15 m + 15 m = 30 m

So one bus = 15 m

Six cricket bats lie end to end under the 6 m crocodile.

1+1+1+1+1+1=6

So one cricket bat = 1 m

Page 12 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

Why it happens: The picture puts the buses exactly below the whale, and the bats
exactly below the crocodile. When equal things fill a known length, we share that
length out equally among them.

Q2 How many buses would be equal to the length of two blue whales?

Length about 30 metres

Length about 6 metres

4m
3m

The pictures on page 83: a blue whale with two buses below it, a giraffe in a barrel, an ostrich and a
crocodile with cricket bats below it.

4 buses.

One whale = 30 m, so two whales = 30 + 30 = 60 m
One bus = 15 m

15 + 15 = 30 → 2 buses make one whale

15 + 15 + 15 + 15 = 60 → 4 buses make two whales

Page 13 of 58

as e
Class 4 Maths Chapter 6 Measuring Length
a g l AglaSem · NCERT Solutions

co m
m.
Why it happens: Two buses fit along one whale. So for two whales we need two

m as e
l
buses twice over, that is 4 buses.

m .co a g
l a se
a g
Q3 How many cricket bats will be needed to measure one whale?

co m
e m . ag
l as

a g

co m
em.
m l as
m .co a g
ase
Length about 30 metres

agl
m a s
m .co agl
l a se
a g
Length about 6 metres

co m
4m
m .
m
3m
as e
.co a g l
se m
g l a
a
se m
com g l a
m . a
e
The pictures on page 83: a blue whale with two buses below it, a giraffe in a barrel, an ostrich and a

l a s
ag
crocodile with cricket bats below it.

m
30 cricket bats.

. co
em
m l as
.co a g
One cricket bat = 1 m

se m One whale = 30 m
g l a
a c
1 m laid down 30 times = 30 m
m .
m a s e
. co agl
So we need 30 bats

e m
g l as
a

co m
m .
m ase
.co


a g l Page 14 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

Why it happens: Each bat covers exactly 1 m. To cover 30 m we must lay the bat
down 30 times, one after another.

Did you know? The blue whale is the biggest animal on the earth.

Q4 If two ostriches stand one above another, their height will be equal to the height of
______________.

Length about 30 metres

Length about 6 metres

4m
3m

The pictures on page 83: a blue whale with two buses below it, a giraffe in a barrel, an ostrich and a
crocodile with cricket bats below it.

Equal to the crocodile — the crocodile is about 6 m long.

One ostrich = 3 m tall

Two ostriches, one above the other = 3 + 3 = 6 m

In the picture, only the crocodile measures 6 m

Page 15 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

Why it happens: Standing one above the other means the two heights are added. 6
m matches the crocodile, and not the giraffe in the barrel, which is 4 m.

Tip: The book gives the crocodile's 6 m as a length, because a crocodile lies flat.
Stood on its tail, it would be 6 m tall.

Q5 How many crocodiles will be equal to the length of a blue whale?

Length about 30 metres

Length about 6 metres

4m
3m

The pictures on page 83: a blue whale with two buses below it, a giraffe in a barrel, an ostrich and a
crocodile with cricket bats below it.

5 crocodiles.

Page 16 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

One crocodile = 6 m, one whale = 30 m

6, 12, 18, 24, 30

That is 6 counted 5 times

So 5 crocodiles are as long as one blue whale

Why it happens: We skip-count by 6 until we reach 30 and see how many jumps it
took. Five jumps of 6 m make 30 m.

Let Us Observe — Page 84
Measuring Small Things

Q1 Can you think how to measure a small thing like an eraser or a rice grain?

Yes. We use a smaller unit called the centimetre (cm), and a scale.

1. A metre rope is far too big for a rice grain. So we look at a standard metre scale.
2. The metre scale is divided into 100 equal parts.
3. The length of each one of those parts is called one centimetre (cm).
4. Put the thing on the scale so that one end is exactly at 0, and read the number at the other
end.

each red bar = 1 cm

0 1 2 3 4 5 6 7 8 9 10

A 0 to 10 scale. The gap between two marks next to each other is one centimetre.

1 metre (m) = 100 centimetre (cm)

Page 17 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

Why it happens: A small thing needs a small unit. If the unit is bigger than the
thing, the answer is always “less than one”, which tells us nothing.

Q2 Compare the metre rope with the measuring tape used by a tailor. Is the length of
both the same or different?

metre rope

tailor’s measuring tape

both are 1 m long

The 1 m rope and the tailor’s tape laid one below the other.

Their length is the same. Both are 1 m long.

Metre rope = 1 m

Tailor's measuring tape = 1 m = 100 cm

The difference is not the length. It is what is written on them:

The rope is plain. It can only tell us “one whole metre”.
The tape has marks and numbers. It can also tell us 1 cm, 7 cm, 45 cm and so on.

Why it happens: The tape is a metre rope that has been cut into 100 equal parts
with marks. The total length does not change when we mark it.

Page 18 of 58

as e
Class 4 Maths Chapter 6 Measuring Length
a g l AglaSem · NCERT Solutions

co m
m.
Observe the measuring tape carefully. What do you notice?
e
Q3

m l as
m.co a g
a se

ag l
each red bar = 1 cm
co m
em . ag
g l as
a
0 1 2 3 4 5 6 7 8 9 10
co m
The measuring tape on page 84, with its marks and numbers. m.
m l a se
. co ag
e m
l as
These are the things we notice on the tape:

a g It has many small marks along one edge.

m
Numbers are written beside the marks: 0, 1, 2, 3 … 10 and further.
a s
The counting starts at 0, not at 1.
m .co agl
l a se
All the gaps are equal. The gap between two marks next to each other is 1 cm.
a g
The red bar in the book is exactly one such gap, so one red bar is 1 cm.
The red bar repeated 10 times makes 10 cm, and repeated 100 times makes 1 m.

co m
m .
m be the same size. as e
l
Why it happens: Measuring is counting equal gaps. That is why the gaps on a tape
. coall a g
m
must

ase
agl
m
Tip: The number 100 on a metre tape does not mean 100 marks. It means the

a se
com g l
distance from 0 is 100 gaps of 1 cm each.

m . a
ase
agl
Discuss how these marks help us measure clearly.
m
Q4

. co
e m
m l as
.co g

m a
l a se
ag each red bar = 1 cm
.c
s e m
m a
e m . co agl
0 1 2 glas 3 4 5 6 7 8 9 10
a

co m
m .
m ase
.co


a g l Page 19 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

The marks on the tape cut one metre into 100 equal pieces.

The marks help us in three ways:

They cut the tape into equal pieces of 1 cm, so everyone gets the same answer.
We do not have to count the pieces one by one. The number beside the mark tells us how
many centimetres we have already covered.
They let us say a length exactly — 7 cm, not just “a little less than my hand”.

Without marks: “the pencil is about two fingers long”

With marks: the pencil is 10 cm long

Why it happens: Fingers, hands and footsteps are different for every child. A
centimetre is the same for everybody, so the marks make our answers match.

Q5 1/2 m = _____ cm, 1/4 m = _____ cm

1/2 m = 50 cm and 1/4 m = 25 cm.

1 m = 100 cm

1 m = 1/2 m + 1/2 m

50 + 50 = 100 → 1/2 m = 50 cm

1 m = 1/4 m + 1/4 m + 1/4 m + 1/4 m

25 + 25 + 25 + 25 = 100 → 1/4 m = 25 cm

Page 20 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

1m

1/2 m 1/2 m

1/4 m 1/4 m 1/4 m 1/4 m

The 1 m rope, the two half-metre ropes and the four quarter-metre ropes.

Why it happens: The half-metre rope is half of the metre rope, so it must be half of
100 cm. The quarter-metre rope is half of the half, so it is half of 50 cm.

Check it yourself: 25 + 25 = 50, and 50 + 50 = 100. The ropes fit together exactly.

Let Us Do — Pages 85 to 89
Measuring Small Things

Q1 Measure each object using a scale.

How to measure:

1. Put the 0 mark of the scale exactly at one end of the object.
2. Keep the scale straight along the object, next to the dotted red line the book draws.
3. Read the number at the other end. That number is the length in cm.
4. For the tall green carton, measure along the dotted line down its front edge.

Page 21 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

eraser — 4 cm

pencil — 10 cm

comb — 10 cm

tall green carton (measured along the dotted edge) — 11 cm

0 1 2 3 4 5 6 7 8 9 10 11 12

The four objects on page 85 laid against a centimetre scale.

Sample answer (measured on the printed page):

OBJECT LENGTH

Eraser 4 cm

Pencil 10 cm

Comb 10 cm

Tall green carton 11 cm

Why it happens: A scale measures the distance from 0. If you start at 1 instead of 0,
every answer comes out 1 cm short.

Tip: Measure in your own book too. If your answer is 1 cm away from ours, check
that the 0 mark was really at the end of the object.

Page 22 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

Q2 Write the names of the objects in increasing order of length.

eraser — 4 cm

pencil — 10 cm

comb — 10 cm

tall green carton (measured along the dotted edge) — 11 cm

0 1 2 3 4 5 6 7 8 9 10 11 12

The four objects on page 85 laid against a centimetre scale.

Increasing order means from the shortest to the longest.

eraser 4 cm pencil 10 cm comb 10 cm carton 11 cm

4 is the smallest, then 10, then 10, then 11

Sample answer:

Eraser Pencil Comb Tall green carton

4 cm 10 cm 10 cm 11 cm

Why it happens: Once every object has a number in the same unit, we simply put
the numbers in order from small to big.

Tip: The pencil and the comb come out nearly the same, about 10 cm. So they may
swap places. Measure both very carefully before you write them down.

Page 23 of 58

as e
Class 4 Maths Chapter 6 Measuring Length
a g l AglaSem · NCERT Solutions

co m
m.
Estimate the lengths of the following and compare your responses with your
e
Q3

co1mcm in length. Verify by measuring. l
friends, in the grade. Write some examples of things that can be lesser than or
equal.to g as
em a
a s
a gl

m
This is the table as it is printed in your book:
. co ag
m
se THAN
LENGTH OF EQUAL TO 1
l a
MORE LESS THAN 1 ACTUAL
ITEMS CM ag1 CM CM MEASUREMENT

A fingernail
co m
e m.
m l as
.co
An eraser

a g
se m
l a
An ant

g
a A grain of wheat
m a s
.co agl
A rajma seed

a s em
agl then measure and fill the last column):
Sample answer (first tick your guess,

LENGTH OF EQUAL TO 1 MORE THAN LESS THAN 1
co
ACTUAL
m
m .
se
ITEMS CM 1 CM CM MEASUREMENT

com l a
. ag about 1 cm
sem
A fingernail ✔

a An eraser
agl ✔ about 4 cm

se m
com l a
An ant ✔ less than 1 cm

. a g
m
ase
A grain of wheat ✔ less than 1 cm

A rajma seed agl ✔ about 2 cm

co m
m .
Things that are 1 cm long or shorter: a grain of rice, a mustard seed, a shirt button, a staple

m ase
l
pin, a chalk piece that is nearly finished, the head of a matchstick, a small bead.
.co a g
m Why it happens: One centimetre is about as wide as your little fingernail. Anything
l a se
ag that fits inside one gap on the scale is less than 1 cm.
.c
s e m
m a
e m . co agl
as
Tip: Lay the small thing on the scale from the 0 mark. If it does not reach the 1 mark,
it is less than 1 cm.
a g l

co m
m .
m as e
.co


a g l Page 24 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

Q4 Take three toy cars and find out how far each one can go. You can use a small
wooden ramp, or you might like to make a ramp using any material that you have.
Measure the distance each of your cars travels using measuring tape and write the
answers in cm.

How to do it:

1. Rest one end of a board or a thick book on a pile of books to make a ramp.
2. Let the first car go from the top of the ramp without pushing it.
3. Mark where the car stops with a chalk dot.
4. Lay the measuring tape from the bottom of the ramp to the chalk dot. Read the cm.
5. Do the same for the other two cars, from the same spot on the ramp.
6. Rank 1 for the longest distance, then 2, then 3.

This is the table as it is printed in your book:

CAR DISTANCE FROM THE RAMP RANK

Car 1 _______ cm

Car 2 _______ cm

Car 3 _______ cm

Sample answer:

CAR DISTANCE FROM THE RAMP RANK

Car 1 85 cm 2

Car 2 120 cm 1

Car 3 60 cm 3

120 is the biggest, then 85, then 60

So Car 2 wins, Car 1 is second and Car 3 is third

Why it happens: Every car starts from the same place on the same ramp. So the
only thing that changes is the car, and the distance tells us which one rolls best.

Page 25 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

Tip: 120 cm is more than a metre. You can also write it as 1 m 20 cm.

Page 26 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

Q5 Find the longest and the shortest route in this treasure hunt. You can go around the
obstacles but cannot jump over them. You can only walk on the yellow tiles and not
on the grass. Can you find the length of your route in centimetres? Look for the 1
cm clue in the map.

1 cm
1 cm

START

The treasure-hunt map from page 87. The yellow squares are the tiles you may walk on,
the green is grass, and the four coloured circles are the obstacles — the octopus, the
lion, the hippo and the snake. The small red square is the 1 cm clue.

Page 27 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

The map in your book: a green island covered with a grid of small squares. Yellow tiles wind
through the grass from the word START at the bottom to the treasure chest in the middle. An
octopus, a lion, a hippo and a snake sit on the way. In the top corner a small red square is
marked 1cm across and 1cm down — that is the clue.
How to find the length of your route:

1. The clue says every small square of the grid is 1 cm long on each side.
2. Draw your route with a pencil, staying on the yellow tiles only.
3. Count the squares your pencil crosses, one step at a time, going forward, back, left or right.
4. The number of squares is the length of your route in centimetres.

chest

START

How to count: each dot is 1 cm from the next, so every step of the route is 1 cm.

In the small picture above, the route goes

2 up + 2 right + 1 up + 3 right + 2 down + 2 right

2 + 2 + 1 + 3 + 2 + 2 = 12

So that route is 12 cm long

Count your own route on the book's map in exactly the same way. The shortest route is the one
that uses the fewest squares. The longest route is the one that winds all round the island before
reaching the chest.

Page 28 of 58

as e
Class 4 Maths Chapter 6 Measuring Length
a g l AglaSem · NCERT Solutions

co m
m.
Why it happens: Each step of the route covers one 1 cm square. So counting the

m as e
l
squares is the same as adding 1 cm again and again.
.co a g
a s em
gl Write the number of squares on each straight bit of your route first. Then add
aTip:
those few numbers instead of counting all the squares at one go.

com
m . ag
l a se
Q6 g paper. Measure it using the scale. Length of my hand
Trace your hand on a pieceaof
= ________ cm

co m
em.
m l as

. c o a g
e
How to do
s m it:

1.aPut your hand flat on a sheet of paper with the fingers together.
l
a g
2. Hold the pencil straight up and draw all round your hand.

m a s
.co agl
3. Lift your hand. Now place the scale on the drawing, with the 0 mark at the bottom of your
wrist line.
se m
g l a
4. Read the mark at the tip of your longest finger. That is the length of your hand.
a

co m
m .
m l a se
m .co ag 10
l a se 9
a g
8
se m
com g l a
m . 7 a
a s e
agl 6
5 cm
co m
4m.
m a s e
e m . co agl 3
g l as
a 2
c
m .
m
1
a s e
e m . co 0 agl
ag las

co m
m .
m ase
.co


a g l Page 29 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

The traced hand measured against the scale, from the wrist line to the finger tip.

Sample answer: Length of my hand = 14 cm.

Why it happens: We measure the outline, not the hand itself, because the outline
lies flat and does not move while we read the scale.

Try this: Measure a friend's hand too. Hands are not the same size, so the hand is
not a good unit for everybody — but it is a handy one for you.

Q7 Use your hand to estimate the measurement of any object. Convert into
centimetres. Verify using the scale.

How to do it:

1. First find the length of your hand in cm (from the last question).
2. Lay your hand along the object, end over end, and count how many hands it takes.
3. To change hands into centimetres, add your hand length that many times.
4. Now measure the same object with the scale and compare.

This is the table as it is printed in your book:

OBJECT NUMBER OF ESTIMATE USING ACTUAL MEASURE USING
HANDS HAND THE CM SCALE

1. Length of my _______ cm _______ cm
textbook

2. Height of my _______ cm _______ cm
chair

3. Width of my _______ cm _______ cm
desk

4. Height of a _______ cm _______ cm
flowerpot

Sample answer (taking my hand as 14 cm long):

Page 30 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

OBJECT NUMBER OF ESTIMATE USING ACTUAL MEASURE USING
HANDS HAND THE CM SCALE

1. Length of my 2 14 + 14 = 28 cm 26 cm
textbook

2. Height of my 3 14 + 14 + 14 = 42 cm 44 cm
chair

3. Width of my 4 14 + 14 + 14 + 14 = 56 55 cm
desk cm

4. Height of a 1 14 cm 15 cm
flowerpot

Why it happens: The hand works like a short rope. We repeat it and add, just as we
repeated the 1 m rope to draw a 5 m line.

Tip: The estimate and the real measure will not match exactly, and that is fine. A
good estimate lands close to the real number.

Q8 Ashwin's scale is broken. Can you help him to measure using this scale?

8 16 15 14 13 12 11

9

10

11 card
12 card
13

14

Page 31 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

Ashwin’s two broken scales, with a card placed along each one.

Yes. A broken scale still works. We read the mark at both ends and take the difference.
First card (the dark one, on the upright scale):

Top end of the card is at the mark 8

Bottom end of the card is at the mark 14

Count on: 8 → 9 → 10 → 11 → 12 → 13 → 14

That is 6 jumps of 1 cm

Length = 14 − 8 = 6 cm

Second card (on the flat scale, where the numbers run 16, 15, 14 …):

One end of the card is at the mark 16

The other end is at the mark 12

Count back: 16 → 15 → 14 → 13 → 12
That is 4 jumps of 1 cm

Length = 16 − 12 = 4 cm

Why it happens: A scale measures the distance between two marks. Starting at 0 is
only a habit — it just makes the subtraction easy, because anything take away 0
stays the same.

Try this: Cover the 0, 1 and 2 of your own scale with paper and measure your pencil
starting from 3. Subtract 3 at the end. You get the same length.

Page 32 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

Q9 Fill the blanks on the number line below appropriately.

0cm 10cm 20cm 30cm 40cm __ cm 60cm 70cm 80cm 90cm 100cm
25cm __ cm

0m __ m 1/2 m 3/4 m 1m

The number line on page 89, with three empty boxes.

This is the number line as it is printed in your book:

0cm 10cm 20cm 30cm 40cm __ cm 60cm 70cm 80cm 90cm 100cm
25cm __ cm

0m __ m 1/2 m 3/4 m 1m

The number line on page 89, with three empty boxes.

The three blanks are 50 cm, 75 cm and 1/4 m.

Above the line the numbers go up in tens:

0, 10, 20, 30, 40, 50, 60, 70, 80, 90, 100

The second empty box sits on the mark between 70 and 80, at 75 cm

Below the line the same marks are named in metres:

25 cm is a quarter of 100 cm, so it is 1/4 m

Page 33 of 58

as e
Class 4 Maths Chapter 6 Measuring Length
a g l AglaSem · NCERT Solutions

co m
em.
m l as
.co g
0cm 10cm 20cm 30cm 40cm 50cm 60cm 70cm 80cm 90cm 100cm

m a
25cm 75cm

l a se
a g
0m 1/4 m 1/2 m 3/4 m 1m

. com ag
a s emwith the three boxes filled in.
agl
The same number line

Why it happens: The top row and the bottom row show the same distances in two
co m
units. 25 cm and 1/4 m stand at one place, so they must be the same length.
e m.
m l as
.co a g
a s em25, 50, 75, 100 is skip-counting by 25. That is 1/4 m, 1/2 m, 3/4 m, 1 m.
gl
Tip:
a
om has a decorative border sticker which is 20 a s
. cSonu
em are needed to cover the length of the board
The length of a board is 2 metres. agl
s
Q10
a
agl
cm long. How many such stickers
completely?

co m
m .
e

m l as
.co g
10 stickers.

em a
a s
agl Length of the board = 2 m
se m
com a
1 m = 100 cm, so 2 m = 100 + 100 = 200 cm
. a g l
m
ase
agl
Each sticker = 20 cm. Put them end to end and skip-count by 20:

20, 40, 60, 80, 100, 120, 140, 160, 180, 200
co m
m .
e
We counted 10 jumps
m l as
m .co
So Sonu needs 10 stickers
a g
l a se
ag
.c
s e m
m a
e m . co agl
g l as
a

co m
m .
m as e
.co


a g l Page 34 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

20 cm

1 2 3 4 5 6 7 8 9 10

0m 1m 2m

Ten stickers of 20 cm each, laid end to end along the 2 m board.

Why it happens: Five stickers of 20 cm make 100 cm, that is one metre. The board is
two metres, so it needs five stickers twice over.

Tip: Always change both lengths into the same unit before you compare. Here we
changed metres into centimetres.

Metre and Centimetres — Page 89
Metre and Centimetres

Q1 Ramu and Shamu are using a measuring tape to measure their own height. Ramu
reads his height from the tape as 120 cm and Shamu reads it as 1 m 20 cm. Who is
correct?

Both are correct. Pinki is right.

120 cm = 100 cm + 20 cm
100 cm = 1 m

So 120 cm = 1 m + 20 cm = 1 m 20 cm

Page 35 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

100 cm 20 cm

1m 20 cm

Pinki’s drawing: the same height written in two ways, one below the other.

Pinki draws the height twice. In the first line she calls the long part 100 cm. In the second line
she calls the very same part 1 m. The short part stays 20 cm in both.

Why it happens: 1 m and 100 cm are two names for one length. Changing the name
does not change how tall Ramu is.

Tip: To change cm into m and cm, split the number after the hundreds. 145 cm = 1 m
45 cm and 260 cm = 2 m 60 cm.

Let Us Do — Page 90
Metre and Centimetres

Q1 The Village Sarpanch got the depth of some wells in his village measured by two
different people. a) Fill the blanks such that the depths are the same. i) 2 m = 200
cm ii) __ m = 400 cm iii) 6 m = ____cm iv) __ m = 800m

The rule we use every time is 1 m = 100 cm.

Page 36 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

i) 2 m = 100 + 100 = 200 cm (done for us)

ii) 100, 200, 300, 400 → that is 100 counted 4 times

So 4 m = 400 cm

iii) 6 m = 100 + 100 + 100 + 100 + 100 + 100 = 600 cm

iv) 100, 200, 300, 400, 500, 600, 700, 800 → 100 counted 8 times

So 8 m = 800 cm

DEPTH IN METRES SAME DEPTH IN CENTIMETRES

2m 200 cm

4m 400 cm

6m 600 cm

8m 800 cm

Why it happens: Each metre is 100 centimetres. So to go from metres to
centimetres we add 100 once for every metre — the same as skip-counting in
hundreds.

Note about a printing mistake in the book: part (iv) of the English book is printed
as “__ m = 800m”. It should read 800 cm, and the Hindi book prints it correctly as 800
से .मी. Read it as 800 cm, so the answer is 8 m.

Q2 b) Identify the wells with the same depth and match them.

Change every depth written in m and cm into plain centimetres, then look for the matching
number.

Page 37 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

1 m 40 cm = 100 + 40 = 140 cm

4 m 60 cm = 400 + 60 = 460 cm

2 m 30 cm = 200 + 30 = 230 cm
5 m 50 cm = 500 + 50 = 550 cm

WELL MEASURED BY THE FIRST MATCHES WELL MEASURED BY THE SECOND
PERSON PERSON

1 m 40 cm → 140 cm

4 m 60 cm → 460 cm

2 m 30 cm → 230 cm

5 m 50 cm → 550 cm

Why it happens: Two people measured the same well but wrote the answer in
different units. Once both are in centimetres, the equal ones are easy to spot.

Tip: Going the other way is just as easy. The hundreds become the metres: 460 cm =
4 m 60 cm.

Let Us Explore — Pages 90 to 91
Metre and Centimetres

Q1 Activity: Students will measure their height using a measuring tape. Make a table in
your notebook and complete it.

How to do it:

1. Stick the measuring tape on a wall with the 0 mark touching the floor.
2. One child stands straight against the wall, heels together, looking ahead.
3. A friend puts a ruler flat on the child's head and reads the mark on the tape.
4. Write that number in the Height in cm column.
5. For the last column, split the number after the hundreds: 132 cm = 1 m 32 cm.

Sample answer (your class will have its own names and numbers):

Page 38 of 58

as e
Class 4 Maths Chapter 6 Measuring Length
a g l AglaSem · NCERT Solutions

co m
m.
NAME OF THE STUDENT HEIGHT IN CM HEIGHT IN M

m as e
Aarav
.co
132 cm
a g l
1 m 32 cm

se m
g l a
Bhavya
a
128 cm 1 m 28 cm

Chetan 141 cm 1 m 41 cm

co m
m . ag
se
Divya 98 cm less than 1 m

l a
Eshan
ag 125 cm 1 m 25 cm

co m
m.
Why it happens: 100 cm make one metre. So the hundreds in the number tell us the

m as e
.co l
metres, and whatever is left over stays as centimetres.
a g
a s em
a gl Tip: Everybody must take off their shoes and stand on the same flat floor, or the
heights cannot be compared fairly.
m a s
m.co agl
l a se
Q2 a g
Height of the tallest child is _____.

co m
m .
e

m l as
.co a g
Look down the Height in cm column of your table and pick the biggest number.

a s em
agl NAME OF THE STUDENT HEIGHT IN CM HEIGHT IN M

se m
com a
Aarav 132 cm 1 m 32 cm

. a g l
m
ase
Bhavya 128 cm 1 m 28 cm

Chetan agl 141 cm 1 m 41 cm

co m
.
Divya 98 cm less than 1 m

em
m l as
.co g
Eshan 125 cm 1 m 25 cm

m a
l a se
ag
.c
98, 125, 128, 132, 141

s e m
m a
co agl
The biggest number is 141
.
s em
141 cm = 100 + 41 = 1 m 41 cm
a
agl
Sample answer: The tallest child is Chetan. His height is 141 cm, that is 1 m 41 cm.

co m
m .
m ase
.co


a g l Page 39 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

Why it happens: All the heights are written in the same unit, centimetres. So the
biggest number belongs to the tallest child.

Q3 Height of the shortest child is _____.

Now pick the smallest number in the same column.

NAME OF THE STUDENT HEIGHT IN CM HEIGHT IN M

Aarav 132 cm 1 m 32 cm

Bhavya 128 cm 1 m 28 cm

Chetan 141 cm 1 m 41 cm

Divya 98 cm less than 1 m

Eshan 125 cm 1 m 25 cm

98, 125, 128, 132, 141

The smallest number is 98
98 cm is less than 100 cm, so it is less than 1 m

Sample answer: The shortest child is Divya. Her height is 98 cm.

Why it happens: 98 has only two digits and every other height has three, so 98 is
the smallest without any counting.

Q4 Number of children who are more than 1 m tall _____.

1 m = 100 cm. So we count the heights that are more than 100.

Page 40 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

NAME OF THE STUDENT HEIGHT IN CM HEIGHT IN M

Aarav 132 cm 1 m 32 cm

Bhavya 128 cm 1 m 28 cm

Chetan 141 cm 1 m 41 cm

Divya 98 cm less than 1 m

Eshan 125 cm 1 m 25 cm

132 → more than 100 ✔

128 → more than 100 ✔

141 → more than 100 ✔

98 → less than 100 ✘

125 → more than 100 ✔
Count the ticks: 1, 2, 3, 4

Sample answer: 4 children are more than 1 m tall.

Why it happens: Comparing with 1 m is easy once every height is in centimetres,
because 1 m is simply 100 cm.

Q5 Number of children who are shorter than 1 m _____.

Count the heights that are less than 100 cm.

Page 41 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

NAME OF THE STUDENT HEIGHT IN CM HEIGHT IN M

Aarav 132 cm 1 m 32 cm

Bhavya 128 cm 1 m 28 cm

Chetan 141 cm 1 m 41 cm

Divya 98 cm less than 1 m

Eshan 125 cm 1 m 25 cm

Only 98 cm is less than 100 cm

So the count is 1

Check: 4 children taller than 1 m + 1 child shorter than 1 m = 5 children in the table ✔

Sample answer: 1 child is shorter than 1 m.

Why it happens: Every child is either taller or shorter than 1 m, so the two counts
must add up to the number of children in the table.

Tip: In most Class 4 rooms this answer is 0, because nearly everyone has already
crossed one metre. Use your own table, not ours.

Fencing and Lacing — Page 91
Fencing and Lacing

Q1 Bhola is making a boundary with bricks for his vegetable garden. Colour the bricks
on the boundary. How many bricks will he need to make the boundary?

The picture in your book: a rectangular vegetable bed with rows of small plants inside it. A low
wall of bricks runs all round the bed. On the far side the bricks are already laid and coloured red;
Bhola is kneeling and placing one more. The rest of the wall is drawn in white, with dotted lines
that show where each brick will go.
What to colour: only the bricks that make the wall all round the bed — the two long sides and
the two short sides. The plants inside are not part of the boundary.

Page 42 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

How to count the bricks:

1. Start at one corner and go round the bed once, the same way all the time.
2. Count the bricks on the first long side, then the second long side.
3. Count the bricks on each short side.
4. Add the four numbers. Do not count a corner brick twice.

long side

long side

A plain top view of a brick boundary round a garden bed.

In the drawing above:

top long side = 9 bricks bottom long side = 9 bricks

left short side = 4 bricks right short side = 4 bricks

9 + 9 + 4 + 4 = 26 bricks

Count the bricks on the picture in your book in exactly the same way. The bed there is drawn in
a slanting view, so the far bricks look smaller than the near ones — count one side at a time and
mark each brick with your pencil as you count it.

Why it happens: The wall is a closed ring round the bed. Going round once and
counting is the only way to be sure no brick is missed and none is counted twice.

Tip: The book tells us the word for this: the length of the boundary of an object or
shape is called perimeter.

Page 43 of 58

as e
Class 4 Maths Chapter 6 Measuring Length
a g l AglaSem · NCERT Solutions

co m
m.
Let Us Do — Pages 92 to 94
m as e
.co
Fencing and Lacing (Perimeter)
a g l
a s em
aQ1gl Bhola made the boundary of his gardens in the following ways. Circle the boundary
that is longest.

co m
e m . ag
g l as
a

co m
em.
m l as
m .co a g
l a se
a g 1. plain rectangle 2. corners cut off 3. steps on both sides

m a s
.co agl
Bhola’s three garden boundaries, drawn in bricks.

se m
g l a
a

co m
m .
m ase
.co a g l
se m
g l a
a
se m
com g l a
m . a
ase
1. plain rectangle agl 2. corners cut off 3. steps on both sides

co m
.
m s em
Bhola’s three garden boundaries, drawn in bricks.
a
m . co agl
l a se Circle the third garden — the one with the steps sticking out on both sides.
ag c
.
How to check it yourself:

s e m
m a
co agl
1. Take a piece of thread and lay it right along the boundary of the first garden.

m .
e
2. Pinch the thread where it comes back to the start, and pull it straight against a scale.

g l as
3. Do the same for the other two gardens and compare the three lengths.
a

co m
m .
m ase
.co


a g l Page 44 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

Garden 3 has the longest boundary

Garden 1 is a little shorter

Garden 2 has the shortest boundary

Why it happens: Garden 3 keeps going out and coming back in again. Every step
that goes out must be walked back, so those extra bits make the boundary longer.
Garden 2 has its corners cut off, and cutting a corner is a short cut — so its boundary
is the shortest.

Tip: Gardens 1 and 3 hold about the same amount of soil, but their boundaries are
not the same. Same space inside does not mean same boundary.

Q2 Let us find the perimeter of some shapes using the dot grid. One is done for you.

A B

C
10 cm

E

D

The five shapes on the dot grid on page 92. Every dot is 1 cm from the next. Shape A is
the one already done for you.

On this dot grid every dot is 1 cm from the next one. So each small step of a boundary is 1 cm.
To find the perimeter, walk right round the shape and count the 1 cm steps.

Page 45 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

A B

C

E

D

The five shapes on the dot grid on page 92. Shape A is the one already done for you.

Shape A (the one done for you): 2 + 1 + 1 + 1 + 3 + 2 = 10 cm, just as the book shows.

SHAPE WHERE IT IS ADDING THE 1 CM STEPS PERIMETER

A top left, done for you 2+1+1+1+3+2 10 cm

B long and thin, at the top 4+1+4+1 10 cm

C the big one on the right 3+3+1+1+5+2+1+2 18 cm

D the square at the bottom left 2+2+2+2 8 cm

E the tall one in the middle 2+4+1+2+2+1+1+1 14 cm

Why it happens: The dots are 1 cm apart, so the grid does the measuring for us. We
only have to count the steps and add.

Tip: Put a small mark at your starting corner. Stop counting when you get back to
that mark.

Page 46 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

Q3 a) Colour the boundary with the longest length in blue.

A B

C
10 cm

E

D

The five shapes on the dot grid on page 92. Every dot is 1 cm from the next. Shape A is
the one already done for you.

Colour the boundary of shape C, the big one on the right, in blue. Its perimeter is 18 cm.

A B

C

E

D

Shape C, the longest boundary, coloured blue.

Page 47 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

A = 10 cm B = 10 cm C = 18 cm D = 8 cm E = 14 cm

18 is the biggest number

Why it happens: Shape C takes the most 1 cm steps to walk round, so its boundary
is the longest.

Q4 b) Colour the boundary with the shortest length in green.

A B

C
10 cm

E

D

The five shapes on the dot grid on page 92. Every dot is 1 cm from the next. Shape A is
the one already done for you.

Colour the boundary of shape D, the square at the bottom left, in green. Its perimeter is 8 cm.

Page 48 of 58

as e
Class 4 Maths Chapter 6 Measuring Length
a g l AglaSem · NCERT Solutions

co m
e m.
m l as
A
m .co B
a g
l a se
g
C
a

co m
. ag
E
e m
D
g l as
a

co m
em.
m l as
m .co a g
l a se
a g
m
Shape D, the shortest boundary, coloured green.
a s
em
.co agl
a s
l D = 8 cm E = 14 cm
18gcm
A = 10 cm B = 10 cm C = a

m
8 is the smallest number
. co
e m
as
D is a square with each side 2 cm: 2 + 2 + 2 + 2 = 8
m l
m .co a g
a s eWhy
agl it happens: Shape D is the smallest of the five shapes, so walking round it
takes the fewest 1 cm steps.
se m
com g l a
m . a
ase
agl

co m
m .
m as e
.co a g l
se m
g l a
a c
m .
m a s e
e m . co agl
g l as
a

co m
m .
m ase
.co


a g l Page 49 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

Q5 c) Tick the shapes with the same length.

A B

C
10 cm

E

D

The five shapes on the dot grid on page 92. Every dot is 1 cm from the next. Shape A is
the one already done for you.

Tick shape A and shape B. Both have a perimeter of 10 cm.

A B

C

E

D

Shapes A and B, the two boundaries that are the same length.

Page 50 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

A = 10 cm B = 10 cm

C = 18 cm D = 8 cm E = 14 cm

Only 10 comes twice

Why it happens: Shape B is long and thin and shape A is short and fat, yet both take
10 steps of 1 cm to go round. Shapes that look quite different can still have the same
perimeter.

Q6 Do any of the following shapes have the same perimeter? Tick them.

A) B) C)

D) E) F)

The six shapes A) to F) on page 93, drawn on a 1 cm dot grid.

Yes. Count the 1 cm steps round each shape on the dot grid.

Page 51 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

A) B) C)

D) E) F)

The six shapes A) to F) on page 93, drawn on a 1 cm dot grid.

SHAPE ADDING THE 1 CM STEPS PERIMETER

A) 4+1+1+1+3+2 12 cm

B) 2+3+2+3 10 cm

C) 2+1+1+2+1+1+2+2 12 cm

D) 4+3+4+3 14 cm

E) 1+2+3+1+4+3 14 cm

F) 4+3+2+1+2+2 14 cm

Tick these:

A) and C) — both have a perimeter of 12 cm.
D), E) and F) — all three have a perimeter of 14 cm.

Only B) is left out. It is the only shape with a perimeter of 10 cm.

Why it happens: D is a plain rectangle while E and F have steps in them. The steps
push the boundary out and pull it back by the same amount, so the total stays 14
cm.

Page 52 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

Tip: For a rectangle you can add the long side and the short side, then double it. For
D: 4 + 3 = 7, and 7 + 7 = 14.

Q7 Tick the garden with the minimum perimeter.

1 2 3

The three gardens on page 93, drawn on a 1 cm dot grid.

Tick the first garden, the plain rectangle. Its perimeter is the smallest, 18 cm.

1 2 3

The three gardens on page 93, drawn on a 1 cm dot grid.

GARDEN ADDING THE 1 CM STEPS PERIMETER

1 (plain rectangle) 4+5+4+5 18 cm

2 (with a slot cut into the top) 2+2+1+2+2+5+5+5 24 cm

3 (narrow on top, wide below) 3+2+1+3+5+3+1+2 20 cm

Page 53 of 58

as e
Class 4 Maths Chapter 6 Measuring Length
a g l AglaSem · NCERT Solutions

co m
em.
18 cm, 20 cm, 24 cm
m l as
.co
The smallest is 18 cm → garden 1
m a g
l a se
g
aWhy it happens: Minimum means the least. The slot in garden 2 adds two extra

co m
walls going in and one coming across, so its boundary grows a lot. The plain
rectangle has no extra walls at all.
em . ag
g l as
a
Did you know? A farmer who wants to spend the least on fencing picks the shape

co m
m.
with the smallest perimeter.

m as e
.co a g l
a s em
agl Estimate and measure the perimeters of shapes around you using a scale and write
Q8
them in the space given below.

m a s
S. OBJECT
em
.co
ESTIMATED PERIMETER IN ACTUAL MEASURE IN
agl
a s
gl
NO. CM/M CM/M

1. Desk
a

co m
2. Blackboard
m .
m as e
.co3. Classroom
a g l
a s em floor

agl
4.

se m
com g l a
. a
5.

m
ase
agl
6.

co m
m .
m as e
.co
How to do it:
a g l
a s em1. First look at the thing and guess the total length all round it. Write that guess.
agl 2. Now measure each side with a scale or a measuring tape.
.c
3. Add all the sides. That sum is the perimeter.
s e m
m a
. co agl
4. Use cm for small things and m for big things like the classroom floor.

e m
l as
This is the table as it is printed in your book:
g
a

co m
m .
m ase
.co


a g l Page 54 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

S. OBJECT ESTIMATED PERIMETER IN ACTUAL MEASURE IN
NO. CM/M CM/M

1. Desk

2. Blackboard

3. Classroom
floor

4.

5.

6.

Sample answer (your classroom will give its own numbers):

S. OBJECT ESTIMATED ACTUAL HOW IT WAS
NO. PERIMETER MEASURE ADDED

1. Desk 200 cm 200 cm 60 + 40 + 60 + 40

2. Blackboard 600 cm 590 cm 200 + 95 + 200 + 95

3. Classroom 30 m 28 m 8+6+8+6
floor

4. My notebook 80 cm 86 cm 25 + 18 + 25 + 18

5. Classroom 600 cm 580 cm 200 + 90 + 200 + 90
door

6. Window 400 cm 440 cm 120 + 100 + 120 + 100

Why it happens: The perimeter is the length of the boundary, so we simply add the
lengths of all the sides that make that boundary.

Tip: Measure the opposite sides of a rectangle too, to be sure they match. For a
rectangle you can add one long side and one short side and then double the answer.

Page 55 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

Q9 Draw three different shapes with perimeter of 20 cm.

On a 1 cm dot grid, draw shapes whose 1 cm steps add up to 20.

20 cm 20 cm

20 cm

Three different shapes drawn on a 1 cm dot grid, each with a perimeter of 20 cm.

SHAPE ADDING THE SIDES PERIMETER

A rectangle 6 cm by 4 cm 6+4+6+4 20 cm

A rectangle 7 cm by 3 cm 7+3+7+3 20 cm

An L shape 4+2+2+2+6+4 20 cm

You could also draw a square of side 5 cm, because 5 + 5 + 5 + 5 = 20.

Why it happens: For a rectangle, the long side and the short side together must
make 10 cm, because 10 + 10 = 20. So 6 and 4, or 7 and 3, or 5 and 5 all work.

Page 56 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

Try this: Cut a 20 cm piece of thread. Any closed shape you bend it into has a
perimeter of 20 cm.

Chapter at a glance
Height, width, breadth and depth are all names for a length measurement.
We make 1 m, 1/2 m and 1/4 m ropes: 1 m = 1/2 m + 1/2 m and 1 m = 1/4 m + 1/4 m + 1/4 m
+ 1/4 m.
Small things need a small unit. A metre scale is cut into 100 equal parts, and each part is 1
centimetre (cm).
1 metre (m) = 100 centimetre (cm), so 1/2 m = 50 cm and 1/4 m = 25 cm.
The same height can be written two ways: 120 cm is the same as 1 m 20 cm.
The length of the boundary of a shape is called its perimeter. On a 1 cm dot grid we count
the 1 cm steps all round.

Page 57 of 58

Class 4 Maths Chapter 6 Measuring Length AglaSem · NCERT Solutions

Quick revision

UNIT OR IDEA SHORT HOW BIG IT IS EXAMPLE FROM THE
FORM CHAPTER

Metre m the length of our 1 m rope A classroom door is about 2 m
high

Half metre 1/2 m 50 cm Two 1/2 m ropes make one 1 m
rope

Quarter metre 1/4 m 25 cm Four 1/4 m ropes make one 1 m
rope

Centimetre cm one red bar on the tape A rajma seed is about 1 cm long

Metre to centimetre 1 m = 100 cm 1 m is cut into 100 equal 2 m = 200 cm, 6 m = 600 cm
parts

Two ways to say one cm or m and 120 cm = 1 m 20 cm Ramu and Shamu are both right
height cm

Perimeter — the length all round a A 2 cm by 2 cm square has
closed shape perimeter 8 cm

Dot grid — dots placed 1 cm apart Count the 1 cm steps around the
shape

Scale and measuring — tools marked in centimetres Use them for a pencil, a plant or
tape your height

Page 58 of 58