Is 663 divisible by 2 3 4 5 6 9 10?

Answer 1

By 3 only.

It is not divisible by 2, 4, 5, 6, 9 & 10.

Division tests:

• 2:

If the number is even, ie if the last digit is even (0, 2, 4, 6, 8) it is divisible by 2.

633 is odd (last digit is 3 which is not an even digit), so 633 is not divisible by 2.

• 3:

Sum the digits; if the sum is divisible by 3, the original number is divisible by 3.

(Can repeat the summing until a single digit remains; if this digit is 3, 6 or 9 (ie divisible by 3) then the original number is divisible by 3.)

6 + 6 + 3 = 15

1 + 5 = 6

6 is divisible by 3, so 663 is divisible by 3.

• 4:

Add the last (units) digit to twice the previous (tens) digit; if this sum is divisible by 4, so is the original number.

(Can repeat summing until a single digit remains; if this digit is 4 or 8 (ie divisible by 4) then the original number is divisible by 4.)

6 x 2 + 3 = 15

1 x 2 + 5 = 7

7 is not divisible by 4, so 663 is not divisible by 4.

Note: all multiples of 4 are even; 633 is odd so it cannot be divisible by 4 (the above test does not need to be done).

• 5:

The last digit of the number must be 0 or 5.

3 is not 0 nor 5, so 663 is not divisible by 5.

• 6:

Number must pass the 2 and 3 tests (above).

Fails 2 test (above), so 663 is not divisible by 6.

• 9:

Sum the digits; if the sum is divisible by 9, the original number is divisible by 9

(Can repeat the summing until a single digit remains; if this digit is 9 (ie divisible by 9) then the original number is divisible by 9)

6 + 6 + 3 = 15

1 + 5 = 6

6 is not 9, so 663 is not divisible by 9.

• 10:

Last digit must be 0.

3 is not 0, so 663 is not divisible by10.

Answer 2

663