Divisibility Rules Workbook-1
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A number will be divisible by 2 iff the digit at the unit place is divisible by 2.
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A number will be divisible by 3 iff the sum of digits of the number is divisible by 3
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A number will be divisible by 4 iff last two digits of the number together are divisible by 4.
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A number will be divisible by 5 iff digit at the unit place is either 0 or 5.
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A number will be divisible by 6 iff the digit at the unit place of the number is divisible by 2 & sum of all digits of the number is divisible by 3.
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Divisibility test of 7: Make two set of three nos. starts from unit digit then add the alternate sets, and find out the mutual difference, if it is 0 or any multiple of 7 then the given no. is divisible by 7.
e.g., 001234567
567 + 001 – 234 = 334
Since 334 is not divisible by 7 the given no. is also not divisible by 7.
The same test is applicable for 11 & 13. In these cases we have to see the result is divisible by 11 or 13 respectively or not.
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A number will be divisible by 8 iff the last 3 digits, all together, is divisible by 8.
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A number will be divisible by 9 iff sum of all it’s digits is divisible by 9.
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A number will be divisible by 10 iff it’s last digit is 0.
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A number will be divisible by 11, iff the difference between the sum of the digits at even places and sum of the digits at odd places is a multiple of 11.
e.g., 1298, 1221, 123321, 12344321, 1234554321, 123456654321, 795432
