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Super Simple Divisibility Rules

You’ve got 120 pieces of pizza and want to know whether or not you can split them evenly within your group.

Rather than whip out the calculator, use these simple shortcuts to do the math in your head:

Divisible by 2 if the last digits are 0, 2, 4, 6, or 8. (e.g. 210)
Divisible by 3 if the sum of the digits is divisible by 3 (e.g.514 because the digits add up to 9, which is divisible by 3).
Divisible by 4 if the last two digits are divisible by 4. (e.g.1536 because 36 is divisible by 4).
Divisible by 5 if the last digit is 0 or 5. (e.g.7705)
Divisible by 6 if it passes the rules for both 2 and 3. (e.g.804)
Divisible by 9 if the sum of the digits is divisible by 9 (e.g.3690 since 3 +6 + 9 + 0 = 18, which is divisible by 9).
Divisible by 10 if the number ends in a 0. (e.g.6810)
Divisible by 12 if the rules for divisibility by 3 and 4 apply.

Example: The 120 slices of pizza may be evenly distributed into groups of 2, 3, 4, 5, 6, 8, 10 so on.