Rules of divisibility

How can you tell if a number is divisible by 4 without actually carrying out the division calculation?

How can you tell if a number is divisible by 8 without actually carrying out the division calculation?

There is a nifty way of finding if a large number is divisible by 3, but you do need to know the 3 times table.

To see if a number is divisible by 6 we have to use the tests of divisibility for 2 and 3.