Question

Write the divisibility rules of 3 and 4

Answer 1

Answer:

DIVISIBILITY RULE FOR 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

This rule can be repeated when needed:

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

DIVISIBILITY RULE FOR4=The last 2 digits are divisible by 4

1312 is (12÷4=3) Yes

7019 is not (19÷4=4 3/4) No

A quick check (useful for small numbers) is to halve the number twice and the result is still a whole number.

12/2 = 6, 6/2 = 3, 3 is a whole number. Yes

30/2 = 15, 15/2 = 7.5 which is not a whole number. No

5

The last digit is 0 or 5

Answer 2

Answer:

A number is divisible by 3 if the sum of all the digits is divisible by 3.

For example 372

The sum of digits =3+7+2=12, 12 is divisible by 3 so 372 is also divisible by 3.

A number is said to be divisible by 4 if the last two digits of a number is divisible by 4.

For example 1036

The last 2 digits that is 36 is divisible by 4 so 1036 also is divisible by 4.