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Divisibility by 4
rule: A number is divisible by 4 if the number formed by the two extreme right

digits is divisible by 4 or the last two digits are zeros.
Examples: (a) 148 is divisible by 4 because 48 ÷ 4 = 12

(b) 3100 is divisible by 4 because the last two digits are 00.
Divisibility by 5

rule: A number is divisible by 5 if the number ends with 5 or 0.
Examples: 95 and 130 are divisible by 5.

Divisibility by 6

rule: A number is divisible by 6 if it is divisible by both 2 and 3.
Example: 54 is divisible by 2 as its ones digit is 4.

54 is also divisible by 3 as the sum of digits 5 + 4 = 9 and 9 ÷ 3 = 3.

So, 54 is divisible by 6 as well.
Divisibility by 9

rule: This is similar to divisibility by 3. If the sum of the digits of a number is
divisible by 9, then the number itself is divisible by 9.

Example: In 63, 6 + 3 = 9 and 9 ÷ 9 = 1
So, 63 is divisible by 9.

Divisibility by 10

rule: Numbers ending in 0 are divisible by 10.
Examples: 80, 500, 1530 are divisible by 10.

Think Tank Logical Thinking
Check if your area PIN Code is divisible by 2, 3 and 5.

Practice time 5c

1. State whether the following statements are true (T) or false (F).

(a) 243 is divisible by both 9 and 3.

(b) A number that is divisible by 5 is also divisible by 10.

(c) A number that is divisible by 6 will always be divisible by 3.

(d) If the sum of the digits of any number is a multiple of 9, the number is
divisible by 3.

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