Divisibility Rules
General Explanation
In this lesson we will learn to use divisibility rules. Let's review some of the most
important ones:
Sample Problem 1
Is 162 divisible by 9?
Solution
From the divisibility rules, we know that if a number is divisible by 9 then the sum of its digits is 9.
The sum of the digits of 162 is: 1 + 6 + 2 = 9. Since the sum of the digits is divisible by 9, then 162 is divisible by 9. Sample Problem 2
Is 271 divisible by 10?
Solution
We know that if a number is divisible by 10 it must end in a 0. Since 271 ends in 1, it is not divisible by 10.
