Divisibility Rules

How to divide numbers easily- By Saif Kader

Rules for 2

If the number's last digit ends in an even number, then it is divisible by 2.

For ex., 34 has 4, which is divisible by 2, but 33 is not.

Rules for 3 and 9

The rule for 3 and 9 is if you add all the digits of a number and the sum is divisible by 9, then the number is divisible by 3 and 9. If the sum of the number is divisible by 3, then it is not nessecarily divisible by 9.

For ex., if you take the number 378, then 3+7+8 =18, and 18 is divisible by 3 and 9, so 378 is divisible by 3 and 9.

Rules for 4

If the number's last two digits are divisible by 4, then the number is divisible by 4.

For ex., 132's last 2 digits are 32 which is divisible by 4, so 132 is divisible by 4.

Rules for 5 and 10.

If the number ends in 0 or 5, then the number is divisible by 5. If the number only ends in 0 then it is divisible by 10.

For ex., 230 ends in 0, so it is divisible by 5 and 10.

Rules for 6

If the number is divisible by 2 and 3, then it is dividisible by 6.

For ex., 114 ends in 4 which is divisible by 2, and 1+1+4=6, which is divisible by 3, so 114 is divisible by 2 and 3 p, so it is also divisible by 6.

Rules for 7

First double the last number and subtract it from the rest of the number. If the difference is divisible by 7, then the number is divisible by 7.

For ex., in 252, 2x2 is 4, and 25-4 is 21, which is divisible by 7.

Rules for 8

A number is divisible by 8 if the last 3 numbers are divisible by 8.

For ex., in 2048, 048 or 48 is divisible by 8, so 2048 is divisible by 8.



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