Question

How to check a number is divisible by 7

Answer 1

sum of all the number must be divisible by 7
for example
5556 is a number
so 5+5+5+6=must be the number which is divisible by 7

Answer 2

To find a number is divisible by 7 or not, below steps are to be taken into consideration.

(a) Determine the unit digit of the given number

(b) Double the unit digit

(c) Subtract the obtained value from the truncated original number

(d) Repeat the steps (a), (b) and (c) till we left with a single digit.

(e) If the resultant unit digit is 7 or 0, the given number is divisible by 7

E.g. Find whether 12271 is divisible by 7

Unit digit-1

Doubled it-2

1227 – 2 = 1225  

Unit digit – 5

Doubled it -10

122 – 10 = 112  

Unit digit=2

Doubled it - 4

11 – 4 = 7  

Hence the obtained result is 7 which is divisible by 7.