This page continues with our series on tests of divisibility.

To find out whether a number is exactly divisible by 3:

Add up the digits of the number.

If the total is divisible by 3 then so is the number.

Eg: 345

3 + 4+ 5 = 12.

12 is divisible by 3 so 345 is also divisible by 3.

To find out if a number is exactly divisible by 6:

Check that it is even.

If it is even, apply the test of divisibility for 3. If the total of the digits is divisible by 3 and the number is even, it is also divisible by 6.

Eg 348

348 is even.

3 + 4+ 8 = 15.

15 is divisible by 3 so 348 is divisible by 6.