NCERT Book Class 9 Mathematics Chapter 3 The World of Numbers

The World of Numbers
3

3.1. The Dawn of Mathematics: The Human Need to
Count
Long before humanity built cities, formulated laws, or studied the stars,
there existed a fundamental, practical necessity: the need to keep count.
Mathematics did not begin in a classroom with equations on a board; it
began in the dirt, on the bark of trees, and on bones.
Imagine you are living thousands of years ago in a small agricultural
settlement along the banks of the Saraswati river. You have a herd
of cattle. Every morning, they go out into the dense forests to graze,
and every evening, they return. How do you ensure that a calf has
not wandered off? Without words for numbers, and without written
symbols, early humans solved this through a concept called one-to-one
correspondence.
For every cow that left the settlement, the herder might place one
pebble in a clay pot. In the evening, for every cow that returned, one
pebble was removed. If the pot was empty at the end of the day, the herd
was safe. If pebbles remained, cows were missing. This simple act of
matching one object to another was the birth of the Natural Numbers
( = {1, 2, 3, 4, … }).

3.1.1 A History Written in Bone
While the decimal place-value system we use today was perfected in
the Indian subcontinent, the earliest physical evidence of humanity
recording natural numbers takes us deep into the heart of Africa. The
first mathematicians did not use paper; they used tally marks carved
into bone.
The Lebombo Bone, discovered in the Lebombo Mountains
between South Africa and Swaziland, dates back approximately
35,000 years. It is a bone featuring 29 distinct, deliberately-carved
uniformly-sized notches. Anthropologists and mathematicians believe
this was not just random scratching, but a tool used as a lunar phase
counter or a menstrual calendar, indicating that early humans were
tracking time through natural numbers.