Explanation:
no calculator ?
1.
3 yes
6 yes
9 no
2.
3 yes
6 yes
9 yes
3.
3 yes
6 yes
9 no
4.
3 no
6 no
9 no
5.
3 no
6 no
9 no
6.
3 yes
6 yes
9 no
7.
3 yes
6 no
9 yes
8.
3 yes
6 yes
9 no
9.
3 yes
6 yes
9 yes
10.
3 no
6 no
9 no
a number is divisible by 3, only if the sum of the digits is divisible by 3.
a number is divisible by 6, only if it is divisible by 3 and by 2 (even number).
a number is divisible by 9, only if the sum of the digits is divisible by 9.