Divisibility Rules Flashcards Preview

Maths > Divisibility Rules > Flashcards

Flashcards in Divisibility Rules Deck (11)
Loading flashcards...
1
Q

A number is divisible by 2 if…?

A

The last digit is even (0,2,4,6,8).

Examples:

128 is

129 is not

2
Q

A number is divisible by 3 if…?

A

The sum of the digits is divisible by 3.

Examples:

381 (3+8+1 = 12, and 12/3 = 4) YES

217 (2+1+7 = 10, AND 10/3 = 3 1/3) NO

3
Q

A number is divisible by 4 if…?

A

The last 2 digits are divisible by 4

Examples:

1312 is

(12/4 = 3)

7019 is not

4
Q

A number is divisible by 5 if…?

A

The last digit is 0 or 5

175 is

809 is not

5
Q

A number is divisible by 6 if…?

A

The number is divisible by 2 and 3

114 (it is even, and 1+1+4 = 6 and 6/3 = 2) Yes

308 (it is even, but 3+0+8 = 11 and 11/3 = 3 2/3) No

6
Q

A number is divisible by 7 if…?

A

If you double the last digit and subtract it from the rest of the number and the answer is: 0 or divisible by 7

(Note: you can apply this rule to that answer again if you want)

Examples:

672 (Double 2 is 4, 67-2 = 63, and 63/7 = 9) Yes

905 (Double 5 is 10, 90-10 = 80, and 80/7 = 11 3/7) No

7
Q

A number is divisible by 8 if … ?

A

The last three digits are divisible by 8

Examples:

109816

(816/8 = 102) Yes

216302

(302/8 = 37 3/4) No

8
Q

A number is divisible by 9 if … ?

A

The sum of the digits is divisible by 9

(Note: you can apply this rule to that answer again if you want)

1629

(1+6+2+9 = 18 and again, 1+8 = 9) Yes

2013

(2+0+1+3 =6) No

9
Q

A number is divisible by 10 if … ?

A

The number ends in 0

220 is

221 is not

10
Q

A number is divisible by 11 if … ?

A

Add and substract digits in an alternating pattern (add first, subtract second, add third, etc). Then the answer must be:

0 or divisible by 11

1364 : (1-3+6-4 = 0) Yes

913 : (9-1+3 = 11) Yes

3729 : (3-7+2-9 = -11) Yes

987 (9-8+7 = 8) No

11
Q

A number is divisible by 12 if … ?

A

The number is divisible by both 3 and 4

Examples:

648

(By 3? 6+4+8 = 18 and 18/3 = 6 Yes. By 4? 48/4 = 12 Yes) Yes

524

(By 3? 5+2+4 = 11, 11/3 = 3 2/3 No. Don’t need to check by 4.) No