Test of Divisibility of Numbers - 2, 3, 4, 5, 6, 8, 9, 10

1) First 2:

Any number whose last digit is even number then that number is divisible by 2

For eg. 102 here last digit is 2 which is divisible by 2.

2) Number 3:

Take any number say 36. If you add each of its digit we get 3 + 6 = 9. Here 9 is divisible by 3 so 36 is divisible by 3.

3) Number 4: If the last two digit of a number is divisible by 4 then that number is divisible by 4. For eg. 301284 here last two digit 84 is divisible by 4 hence 301284 is divisible by 4.

4) Number 5:

If the last digit of a number is 0 or 5 then that number is divisible by 5. For eg. 20 here last digit is 0 therefore the number is divisible by 5.

5) Number 6:

If the number is divisible by both 2 and 3 then number is divisible by 6.

6) Number 9: Just like 3 you add up the digits and see if it is divisible by 9 then that number is divisible by 9. For eg. 981 here 9+8+1 = 18 which is divisible by 9 hence the number 981 is divisible by 9.

7) Number 10: If the last digit of a number is 0 then that number is divisible by 10. For eg. 10, 20, 30 etc.

From the above writing it is clear then only 2,3, 4, 5, 6, 9 and 10 have easy method to determine divisibility. While other numbers do not have clear method of divisibility hence i suggest just keep 2,3,4, 5, 6, 9 and 10 in mind and forget rest of them.