DIVISION :

Rules for Divisibility :

6. Divisibility by 7 : The unit digit of the given number is doubled and then it is subtracted from the number obtained after omitting the unit digit. If the remainder is divisible by 7, then the given number is also divisible by 7.

For example, consider the number 448. On doubling the unit digit 8 of 448 we get 16.

Then, 44 – 16 = 28.

Since 28 is divisible by 7, 448 is divisible by 7.