The following set of rules can help you save time in trying to check the divisibility of numbers.

Is 126 divisible by 3? Sum of digits = 9. Because 9 is divisible by 3, then 126 is divisible by 3.

Is 1,648 divisible by 4? Because 48 is divisible by 4, then 1,648 is divisible by 4.

Is 186 divisible by 6? Because 186 ends in 6, it is divisible by 2. Sum of digits = 15. Because 15 is divisible by 3, 186 is divisible by 3. 186 is divisible by 2 and 3; therefore, it is divisible by 6.

Is 2,488 divisible by 8? Because 488 is divisible by 8, then 2,488 is divisible by 8.

Is 2,853 divisible by 9? Sum of digits = 18. Because 18 is divisible by 9, then 2,853 is divisible by 9.