Write the divisibility tests for 4, 5, 6, 8, 9, 10 and 11 giving your own examples for each.
Answers
Divisibility by 4 A number is divisible by 4
If its that two digits are divisible by 4
Example:
• 212 has last two digits 12
Since 12 is divisible by divisible by 4 212 is
• 1936 has last two digits 36
Since 36 is divisible by divisible by 4 1936 is
• 286 has last two digits 86
Since 86 is not divisible by 4,
Divisibility by 5
A number is divisible by 5, if last digit is 5 or 0.
Example:
• 60 is divisible by 5 as last digit is
0
• 25 is divisible by 5 as last digit is
5
• 39 is not divisible by 5 as last digit is not 0 or 5.
Divisibility by 6
A number is divisible by 6
• It is divisible by 2
• It is divisible by 3
Example:
• 36 is divisible by 2 as last digit is
6.
:D
if
36 has sum of digits 9, which is divisible by 3, so 36 is divisible by 3
Since 36 is divisible by both 2 and 3, it is divisible by 6 • 27 is not divisible by 2 as last digit is not 0, 2, 4, 6, 8
27 has sum of digits 9, which is divisible by 3, so 36 is divisible by 3
Since 27 is not divisible by 2, it is not divisible by 6 • 216 is divisible by 2 as last digit
is 6
216 has sum of digits 9, which is divisible by 3, so 216 is divisible by 3
Since 216 is divisible by both 2 and 3, it is divisible by 6
Divisibility by 8
A number is divisible by 8
If its last 3 digits are divisible by 8 Example:
• 9216 has last three digits 216
Since 216 is divisible by 8, 9216 is divisible by 8
• 2000 has last three digits 000 i.e. 0
Since 0 is divisible by 8, 2000 is divisible by 8
• 1416 has last three digits 416
Since 416 is not divisible by 8, 1416 is not Divisible by 8
Divisibility by 9
If sum of digits of number is divisible by 9,
Then number is divisible by 9 Example:
• 27 has sum of digits 9, which is divisible by 9, so 27 is divisible by 9
• 117 has sum of digits 9, which is divisible by 9, so 117 is divisible by 9
• 758 has sum of digits 20, which is not divisible by 9, so 758 is not divisible by 9
Divisibility by 10
A number is divisible by 10, if last digit is 0.
Example:
• 20 is divisible by 10 as last digit is 0
• 43 is not divisible by 10 as last digit is not 0