What are the divisibility rules for 1-13?

Answer 1

14

Answer 2

0: Every number is divisible by 0

1: Every number is divisible by 1

2: Every even number is divisible by 2

3: If the sum of the digits is divisible by 3, then so is the whole number. Repeat the process if necessary - example: is 4,962 divisible by 3? 4+9+6+2=21 2+1=3 - 3 is divisible by 3. Therefore, 4,962 is also divisible by 3

4: If the last 2 digits of a number are divisible by 4, then so is the whole number

5: A number is divisible by 5 if the number ends in 5 or 0

6: A number is divisible by 6 if it's divisible by both 2 and 3

7: If the last digit doubled subtracted from the number left is equal to a number divisible by 7, then so is the whole number. Repeat the process if necessary - example: is 2,541 divisible by 7? 2*2=4-254=252 2*2=4-25=21 1*2=2-2=0 - 0 is divisible by 7. Therefore, 2,541 is also divisible by 7

8: A number is divisible by 8 if the last 3 digits are divisible by 8

9: If the sum of the digits are divisible by 9, then so is the whole number. Repeat the process if necessary

10: A number is divisible by 10 if the last digit is a 0

11: A number is divisible by 11 if any other digit added together minus every digit left equals a number divisible by 11(not 1) - there is another rule that says that if the answer to the first number minus the second number plus the third number and so on equals a number divisible by 11, then so is the original number

12: A number is divisible by 12 if it is also divisible by 3 and 4

13: If the last digit multiplied by 4 plus the rest of the number is equal to a sum that is divisible by 13, then so is the original number