Amazing Remainder Checking (Divide by 9)

The number 9 is a special number when it is used as a divisor.

Why so?
It produces an amazing feature.

Divide 152 by 9.

Answer is 16 with remainder of 8.

Let's add up the digits of the original number 152.

1 + 5 + 2 = 8. The answer of "8" tallies with the remainder "8" !

This is a quick way to check for correct remainder when divided by 9.

Another example: Divide 321 by 9

Answer is 35 with remainder 6.

Quick check for remainder: 3 + 2 + 1 = 6 !

Example: Divide 4488 by 9 ==> 498 with remainder of 6.

Checking remainder: 4 + 4 + 8 + 8 = 24. Remainder = 24 ?

For this case, proceed by summing up the obtained answer (24).

2 + 4 = 6. This is the remainder!

So, if you get a number (non-one digit), just continue adding up the digits.

Point to note when using this quick check method:

• When the sum of the digits is 9 or an even multiple of 9, it means there is no remainder.


• This check is for divide by 9 only.