The Divisible Rule for 9

9.

- the sum of the digits is divisible by 9.

eg. 1+8+9+7+2+3+6 = 36
3+6 = 9

The Divisibility Rule for 5

5.

- all numbers ending in 0 or 5

eg. 5, 10 , 15, 20, 25, 30, 35, 40