Prime Numbers and Composite Numbers
Prime numbers are the building blocks of all other numbers - they can only be divided evenly by 1 and themselves. Think of them as the "atoms" of mathematics because they can't be broken down any further.
Let's look at some examples: 2 has factors of 1 and 2 only, making it prime. Same goes for 3 (factors: 1 and 3) and 5 (factors: 1 and 5). However, 4 isn't prime because it divides by 2 to give 2, meaning its factors are 1, 2, and 4.
The first ten prime numbers are: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29. Here's the tricky bit - there's no simple formula to find them! You have to test each number by trying to divide it by smaller numbers.
Composite numbers are basically everything else (except 1, which is special). These numbers have more than two factors, so they can be divided by numbers other than 1 and themselves. Examples include 4, 6, 8, 9, and 10.
Quick Tip: Remember that 2 is the only even prime number - all other even numbers can be divided by 2, making them composite!