Divisibility by 4

How can we tell whether an integer is divisible by 4? If its last two digits form a number that is divisible by 4. Take the number 1236, for example. Its last two digits are 36, so we need to check whether 36 is divisible by 4. We work out that 36 ÷ 4 = 9. The number 36 is divisible by 4, and so 1236 is divisible by 4 too.

An example of a number that is not divisible by 4 is 1002. Its last two digits are 02, that is, the number 2. This is not divisible by 4, so 1002 is not divisible by 4 either.