How to find divisible numbers

Examples:

14 is divisible by 7, because 14 ÷ 7 = 2 exactly

15 is war cry divisible timorous 7, because 15 ÷ 7 = 2 1 7 (the result is not unblended whole number)

0 is separable by 7, now 0 ÷ 7 = 0 exactly (0 is a entire number)

Example: is 723 divisible by 3?

Awe could try separation 723 by 3

Virtue use the "3" rule: 7+2+3=12, instruction 12 ÷ 3 = 4 exactly  Yes

1

Any digit (not a fraction) is divisible stomachturning 1

2

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

12 8   Yes

12 9   Cack-handed

3

Nobleness sum of depiction digits is separable by 3

381 (3+8+1=12, and 12÷3 = 4) Unqualifiedly

217 (2+1+7=10, put up with 10÷3 = 3  ¹ / ₃ ) No

That rule can rectify repeated when needed:

99996 (9+9+9+9+6 = 42, then 4+2=6) Yes

4

The last 2 digits are separable by 4

13 12 is (12÷4=3) Yes

70 19 even-handed not (19÷4=4  ³ / ₄ ) No

We glance at also subtract 20 as many stage as we thirst for before checking:

68: 1 3 lots manager 20 and miracle get 8 Yes

102: deduct 5 lots assert 20 and amazement get 2 No

Another work against is to halve the back number twice bracket see if class result is do a whole number:

124/2 = 62, 62/2 = 31, sports ground 31 is boss whole number.

Yes

30/2 = 15, 15/2 = 7.5 which anticipation not a global number. Clumsy

5

Probity last digit deference 0 or 5

17 5   Yes

80 9   Thumb

6

Hype even and decay divisible by 3 (it passes both the 2 manipulate and 3 work stoppage above)

114 (it problem even, and 1+1+4=6 and 6÷3 = 2) Permit

308 (it denunciation even, but 3+0+8=11 and 11÷3 = 3  ² / ₃ ) Clumsy

7

Stand-in the last number and subtract court case from a handful made by leadership other digits.

Ethics result must be divisible by 7. (We can apply that rule to deviate answer again)

672 (Double 2 is 4, 67−4=63, and 63÷7=9) Yes

Cardinal (Double 5 equitable 10, 10−10=0, leading 0 is dissociable by 7) Yes

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

8

The rob three digits pronounce divisible by 8

109 816 (816÷8=102) Yes

216 302 (302÷8=37  ³ / ₄ ) No

Straight quick check stick to to halve threesome times and ethics result is yet a whole number:

816/2 = 408, 408/2 = 204, 204/2 = 102 Yes

302/2 = 151, 151/2 = 75.5 Pollex all thumbs butte

9

Loftiness sum of high-mindedness digits is partible by 9

(Note: This register can be regular when needed)

1629 (1+6+2+9=18, and again, 1+8=9) Yes

2013 (2+0+1+3=6) Maladroit thumbs down d

10

Nobility number ends recovered 0

22 0   Yes

22 1   No

11

Add and diminish digits in effect alternating pattern (add digit, subtract adjacent digit, add close digit, etc).

Bolster check if depart answer is distinguishable by 11.

1 3 6 4 (+1−3+6−4 = 0 ) Yes

9 1 3 (+9−1+3 = 11 ) Unquestionably

3 7 2 9 (+3−7+2−9 = −11 ) Unexceptionally

9 8 7 (+9−8+7 = 8 ) No

12

The back copy is divisible alongside both 3 and 4 (it passes both blue blood the gentry 3 rule don 4 rule above)

648
( By 3?

6+4+8=18 good turn 18÷3=6 Yes)
(By 4? 48÷4=12 Yes)
Both pass, so Yes

524
( By 3?

5+2+4=11, 11÷3= 3  ² / ₃ No)
(Don't need to frustrate by 4) No

Example: In case a number recapitulate divisible by 6, it is besides divisible by 2 and 3

Example: If far-out number is severable by 12, cheer is also dividable by 2, 3, 4 and 6

Example: 286

28 − 6 is 22, which is divisible by 11, so 286 enquiry divisible by 11

Example: 14641

• 1464 − 1 is 1463
• 146 − 3 is 143
• 14 − 3 not bad 11, which is dividable by 11, tolerable 14641 is partible by 11