The natural numbers (or continuing numbers) are the numbers
1,2,3,4…….. used for counting. 0 is sometimes
included as a natural number. Natural numbers have two main
purposes: they can be used for counting (there are 3 apples
on the table), and they can be used for ordering (this is
the 3rd largest city in the country).
For example, the Babylonians developed a powerful place-value system
based essentially on the numerals for 1 and 10. The ancient Egyptians
had a system of numerals with distinct hieroglyphs for 1, 10, and
all the powers of 10 up to one million. A stone carving from Karnak,
dating from around 1500 BC and now at the Louvre in Paris, depicts
276 as 2 hundreds, 7 tens, and 6 ones; and similarly for the number
4,622.