Prime Factorization
A prime number is a natural number greater than 1 whose only factors are 1 and
itself.
A composite number is a natural number greater than 1 that is not prime.
(1 and 0 are neither prime nor composite)
Prime Factorizations means that you can write all composite numbers as
products of prime numbers. The method I use is called the Tree Method.
This is a list of the first few prime numbers you will need to know them.
2, 3, 5, 7, 11, 13, 17, 19, 23, 29 ……..
Divisibility of a number means - can a number be divided into the number evenly
(without a remainder)
The first step in the Tree Method is to find some number that will divide evenly in
the number.
Here are some divisibility tests that will help you find a number.
2 will divide evenly if the last digit of the number is 0, 2, 4, 6, 8
5 will divide evenly if the last digit of the number is 0 or 5
3 will divide evenly if the sum of the digits is 3 or is divisible by 3
10 will divide evenly if the last digit of the number is 0
6 will divide evenly if 2 and 3 divided evenly
4 will divide evenly if the last two digits divide evenly by 4