Because we have 10 fingers.
There are not 10 laws of composite numbers so the question is based on a complete misunderstanding of what composite numbers are!
The US system that is based on the number 10 is the base 10 system. In the base 10 system the numbers roll over every 10; example 10,20,30.
They are based on numbers or units being related to one another numbers by powers of 10.
The metric system is based on numbers that end with a zero(0.1, 0.01,0.001,10, 100, 1000,etc.).
The Metric system is based on the number 10 and its multiples, which includes numbers like 100, 1,000, 10,000, etc.
10
the numbers are based on the rarity of them
Which 10 counting numbers? There is an infinity of counting numbers.
Tidy numbers are numbers that end with a 0 (10 and multiples of 10)
1.379 billion in numbers-------------------------------Depending upon where you are, you will be using the long or short scale:In countries that use the long scale (based on powers of a million) like Europe:billion = bi-million = (10⁶)² = 10¹² → 1.379 billion = 1.379 × 1 billion = 1.379 × 10¹² = 1,379,000,000,000In countries that use the short scale (based on powers of a thousand plus one) like USA:billion = bi-million = (10³)²⁺¹ = (10³)³ = 10⁹ → 1.379 billion = 1.379 × 1 billion = 1.379 × 10⁹ = 1,379,000,000
10:4
There are 10 whole numbers in 10 to 19.