There are 2 ways of finding whether any number is divisible by 8.
Always remember that odd numbers are not divisible by 8, i.e. any number whose last digit is 1, 3, 5, 7 or 9 is not divisible by 8.
Method 1: Any number is said to be divisible by 8 if the last 3 digits of that number is divisible by 8, i.e. number formed by Hundreds, Tens and Ones digit is divisible by 8.
For example: Is 234568 divisible by 8?
Number formed by last 3 digits of number 134568 is 568.
Now 568 ÷ 8 = 71, i.e. 568 is divisible by 8.
So, 234568 is divisible by 8.
Method 2: Any number is said to be divisible by 8, if the figure obtained when you add the Ones digit with double of Tens digit and 4 times of Hundreds digit, is divisible by 8, i.e. number formed by sum of Ones digit, 2 times the Tens digit and 4 times the Hundreds digit is divisible by 8.
For example: Is 234568 divisible by 8?
As per above formula, add Ones digit, i.e. 8 with double of Tens digit, i.e. 2 times of 6, with 4 times of Hundreds digit, i.e. 4 times 5 = 8 + 2 x 6 + 4 x 5 = 8 + 12 + 20 = 40.
Now 40 ÷ 8 = 5, i.e. 40 is divisible by 8.
So, 234568 is divisible by 8.
It is up to you to judge which method is easy, but my vote goes for Method 2.
Practice Questions:
Check whether below numbers are divisible by 8?
a. 424 b. 1616 c. 111112 d. 222224 e. 221
f. 24 g. 363 h. 12457 i. 2840 j. 555
Maths is Fun and Easy 