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

If you need a refresher, a prime number is a whole number that can only be divided by 1 and itself, such as 2, 3, 5 and 7. Durant’s remarkable discovery, officially called M136279841 ...

Prime numbers are special numbers, greater than 1, that have exactly two factors, themselves and 1. 19 is a prime number. It can only be divided by 1 and 19. 9 is not a prime number. It can be ...