2 is the first prime number ... You should end up with a list of 25 prime numbers between 1 and 100. These are shown in the grid below.

So, if p is a prime number then its only factors will be 1 and p itself. Examples: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, ... (the list continues infinitely) Pythagoras Theorem: Definition ...