CompositeNumbers.
A composite number is a positive integer which has a positive divisor other than one or itself.
A list of composite numbers is surprisingly useful in solving math for grades 3 on up and it can't get lost in a shuffle of homework if you're wearing it.
The 121 composites numbers are useful to solve math equations when challenged by numbers such as 51 which is 3x17 or 57 which is 3x19.
The prime factor tree of 72 can be progressively divided by small prime numbers such as 72 = 2x36 = 2x2x18 = 2x2x2x9 = 2x2x2x3x3
to derive a neat base and exponent symetry of 2^3x3^2.
