Why is it useful to know the divisibility of a number? It allows us to determine whether a number is divisible by another number without having to divide them. In this post, we are going to learn the divisibility guidelines for 9.
Criteria for divisibility by 9:
A number is divisible by 9 if the sum of its digits is 9 or a multiple of 9.
is 2610 divisible by 9?
In order to find out we add its digits:
Therefore 2610 is divisible by 9.
is 965 divisible by 9?
We add all the digits:
Since 20 is not divisible by 9, then 965 is not divisible by 9.
To keep learning:
Divisibility guidelines for:
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