1. Objective: Learn to test for divisibility.

2. Divisibility:
One whole number is divisible by another if, after dividing, the remainder is zero.
For example: 18 is divisible by 9 since 18 ÷ 9 = 2 with no remainder.
If one whole number is divisible by another number, then the second number is a factor of the first number.
For example: Since 18 is divisible by 9, 9 is a factor of 18.

3. A divisibility test is a rule for determining whether one whole number is divisible by another.
There is a quick way to find factors of large numbers
Divisibility rules:
A number is divisible by 2… if the last digit is 0, 2, 4, 6 or 8.
A number is divisible by 3… if the sum of the digits is divisible by 3.
A number is divisible by 4… if the number formed by the last 2
digits is divisible by 4.
A number is divisible by 5… if the ones digit is 0 or 5.
A number is divisible by 6… if the number is divisible by BOTH 2 and 3
A number is divisible by 8… if the number formed by the last 3 digits is
divisible by 8.
A number is divisible by 9… if the sum of the digits is divisible by 9.
A number is divisible by 10… if the ones digit is 0.

4. For example: Test the number 4,320 for divisibility by 2,3,4,5,6,8,9, and 10.
Is this number divisible by… 2?
Yes, because the last digit is 0. 3?
Yes, because = 9 and 9 is divisible by 3. 4?
Yes, because the number formed by the last 2 digits (20) is divisible by 4. 5?
Yes, because 4,320 ends in 0. 6?
Yes, because 4320, is divisible by BOTH 2 and 3. 8?
Yes, because the number formed by the last 3 digits (320) is divisible by 8. 9?
Yes, because = 9 , which is divisible by 9.
10?
Yes, because the ones digit is 0.
So, 4,320 is divisible by 2, 3, 4, 5, 6, 8, 9, and 10.

5. Your Example:
Test each number for divisibility by 2,3,4,5,6,8,9 and 10.

6. Homework: Test the following numbers for divisibility by 2,3,4,5,6,8,9, and 10.
582
585
330 45
276