Divisible by:  If:  Examples: 

2  The last digit is even (0,2,4,6,8)  128 is 129 is not 
3  The sum of the digits is divisible by 3 
381 (3+8+1=12, and 12÷3 = 4) Yes
217 (2+1+7=10, and 10÷3 = 3 1/3) No

4  The last 2 digits are divisible by 4 
1312 is (12÷4=3)
7019 is not 
5  The last digit is 0 or 5  175 is 809 is not 
6  The number is divisible by both 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 
7  If you double the last digit and subtract it from the rest of the number and the answer is:

672 (Double 2 is 4, 674=63, and 63÷7=9) Yes
905 (Double 5 is 10, 9010=80, and 80÷7=11 3/7) No

8  The last three digits are divisible by 8 
109816 (816÷8=102) Yes
216302 (302÷8=37 3/4) No

9  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

10  The number ends in 0 
220 is
221 is not 
11 
If you sum every second digit and then subtract all other digits and the answer is:

1364 ((3+4)  (1+6) = 0) Yes
3729 ((7+9)  (3+2) = 11) Yes
25176 ((5+7)  (2+1+6) = 3) No

12  The number is divisible by both 3 and 4 
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 
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