1. Section 2.1 Divisibility Rules
Chapter 2
Section 2.1
Divisibility Rules

2. Rule for 2 If the number ends with an even digit (like 2,4,6,8,0),
then it is divisible by 2.
Example: 1,354,908

3. Rule for 5 If the number ends with a digit of “5” or “0”,
then the number is divisible
by 5.
Example: 3,627,905
8,394,410

4. Rule for 10 If the number ends in a “0” digit, Then the number is
divisible by 10.
Example: 750,230

5. Rule for 3 If you add up the digits of the
number and the total is divisible
by 3,
Then the original number is
divisible by 3.
Example: 1,248 = =15.
15 is divisible by 3, therefore
so is 1,248!

6. Rule for 9 If you add up the digits ofthe number
and the total is divisible by 9,
Then the original number is divisible by 9.
Example: 6,543 = =18.
18 is divisible by 9, therefore
so is 6,543.

7. Rule for 4 If the last two digits in the number are divisible by 4,
Then the original number is
divisible by 4.
Example: 358,912
12 is divisible by 4, therefore
so is 358,912!

8. Rule for 6 If the number is divisible by 2 and 3,
then it is also divisible by 6.
Example: 8,346.
8,346 = last digit even (divisible by 2)
8,346 = = 21 (divisible by 3)
So also divisible by 6!