61 Divisibility Rules

2, 3, 4, 5, 6, 9, 10


“Divisible
BY”
What does it mean?


“Divisible by” means:
If you divide one number by another,
the result is a whole number
WITHOUT a remainder.

Examples:
12 ÷ 6 = 2 No remainder
15 ÷ 5 = 3 No remainder


Divisibility
Rule 2
A number is divisible by 2 if
the last digit is even. (0,
2, 4, 6, 8)
Examples:

78 3470

Review Even numbers: ghosteven


Now You

Try:
572 1464

Which number IS NOT divisible by 2?

249

Need More Practice: Numbers Divisible by 2


WONDERFUL


It ends in a 0,
2, 4, 6, or 8.


Divisibility
Rule 3
A number is divisible by three
if the sum of the digits is
divisible by 3.
Examples:
75

369

7 + 5 = 12 12 ÷ 3 = 4 No Remainder

3 +6 + 9 = 18

18 ÷ 3 = 6

No Remainder


Now You

Try:
572 1464

Which number IS NOT divisible by 3?

279

Need More Practice: Numbers Divisible by 3


The sum is
divisible by 3.


WONDERFUL


Divisibility
Rule 4

A number is divisible by 4 if the last two digits are

divisible by 4.
Examples:
1320

20 ÷ 4 = 5

672 72 ÷ 4 = 18


Now You

Try:
564 4101

Which number IS NOT divisible by 4?

188

Need More Practice: Numbers Divisible by 4


WONDERFUL


The last 2 digits
are divisible by 4.


Divisibility Rule
5A number is divisible by 5 if

the last digit is a 0 or 5.

Examples:
615 ends in a 5
1480 ends on a 0


Now You
Try:

Which number IS NOT divisible by 5?

9820

779

560

Need More Practice: Numbers Divisible by 5


The number ends in a
zero or a five.


Wonderful


Divisibility
Rule 6

A number is divisible by 6 when it is divisible by 2 AND 3.
(prime numbers)
Examples:
408

ends in an even number (2 rule)
sum of the digits is divisible by 3

Review prime and composite numbers:

Prime and Composite Numbers


Now You Try:
Which number IS NOT divisible by 6?

8700

523

7602

Need more practice? Numbers Divisible by 6


Way To Go!!


This number is

divisible by 2 and 3.


Divisibility
Rule 9

A number is divisible by 9 if the sum of the digits
is divisible by 9.
Examples:
963
5445

9 + 6 + 3 = 18 18 ÷ 9 = 2
5 + 4 + 4 + 5 =18 18 ÷ 9 =2


Now You
Try:

Find the number that IS NOT divisible by 9.

9873

636

Need More Practice:
Numbers Divisible by 9 and 10

5541