A prime number is an integer, or whole number, that has only two factors — 1 and itself. Put another way, a prime number can be divided evenly only by 1 and by itself. Prime numbers also must be ...

How to work out which numbers are multiples of three. A class is asked to find a number from a range between 750 and 800 which is a multiple of three. There is also a demonstration of how to find even ...