Divisibility Rules for numbers Pre-Algebra

To find if a  number

is divisible by 2

 

Check to see if the

number is even.

 

It must end in a

0, 2, 4, 6, or 8.

You try!

Is 33 divisible by 2?
yes

no

Rule for 2

94 is even since ends

in a 4

Is 94 divisible by 2?

Yes 94 is divisble by 2!

 

To find if a  number

is divisible by 3

 

Check to see if the

sum of the digits is

divisible by 3.

You try!

Is 33 divisible by 3?
yes

no

Rule for 3

Since 9+4=13

and 13 is not evenly

divisible by 3,

94 is not evenly

divisible by 3

Is 94 divisible by 3?

To find if a  number

is divisible by 4

 

Check to see if the

last 2 digits are

divisible by 4.

You try!

Is 142 divisible by 4?
yes

no

Rule for 4

The last two digits are 20.

 

Since 20 is divisible by 4

120 is divisible by 4.

Is 120 divisible by 4?

To find if a  number

is divisible by 5

 

Check to see if the

last digit is a 0 or 5.

You try!

Is 241 divisible by 5?
yes

no

Rule for 5

Since the last digit is a 0,

120 is divisible by 5.

Is 120 divisible by 5?

To find if a  number

is divisible by 6

 

Check to see if it is

divisible by both 2

and 3.

You try!

Is 246 divisible by 6?
yes

no

Rule for 6

Since 126 is even it is divisible by 2.

 

Since 1+2+6=9 and 9 is divisible by 3,

126 is divisible by 3.

 

Since 126 is divisible by both

2 and 3 it is also divisible by 6. 

Is 126 divisible by 6?

To find if a  number

is divisible by 8

 

Check to see if the

last 3 digits are

divisible by 8.

You try!

Is 808 divisible by 8?
yes

no

Rule for 8

The last 3 digits are 888.

 

Since 888 is divisible by 8,

2,888 is divisible by 8. 

Is 2,888 divisible by 8?

To find if a  number

is divisible by 9

 

Check to see if the

sum of the digits is

divisible by 9.

You try!

Is 234 divisible by 9?
yes

no

Rule for 9

Since 1+4+4=9

and 9 is divisible by 3,

144 is evenly

divisible by 9.

Is 144 divisible by 9?

To find if a  number

is divisible by 10

 

Check to see if the

last digit is a 0.

You try!

Is 2401 divisible by 10?
yes

Rule for 10

 

no

Since the last digit is a 0,

120 is divisible by 10.

Is 120 divisible by 10?

To find if a  number

is divisible by 11

 

Alternately subtract 

then add digits. If

result is divisible by 

11 then so i2 the 

original number

You try!

Is 63,219,619,914 divisible by 11?
yes

Rule for 11

 

no

Since 

4-5+6-8+2-1+0-9=11

this number is divisible

by 11

Is 45,682,109 divisible 
by 11?

To find if a  number

is divisible by 12

 

Check divisibility 

rules for 3 and 4


(3 X 4 = 12)

You try!

Is 263,240divisible by 10?
yes

Rule for 12

 

no

Since the sum of the digits

is 3 then it's divisible by

3. Since 20 is divisible by

4 it's divisible by 4. Since 

both rules apply it's 

divisible by 12.

Is 120 divisible by 12?
Is 7890 divisible by:

2
4
5
3
Answer yes or no.
Is 4,316,280,948 divisible by:

2
5
6
3
4
Answer yes or no.
8

9

10

11

12
Is 8,456,159,112 divisible by:

2
5
6
3
4
Answer yes or no.
8

9

10

11

12
Is 34,488,115,200 divisible by:

2
5
6
3
4
Answer yes or no.
8

9

10

11

12
Is 17,570,710,080 divisible by:

2
5
6
3
4
Answer yes or no.
8

9

10

11

12
Is 7,460,453,801,339
 divisible by:

2
5
6
3
4
Answer yes or no.
8

9

10

11

12
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