How to find whether a number is divisible by 11 ?

How to find whether a number is divisible by 11 ?

Lets take a simple example.. Does 11 divides 154 ?


Here is a trick...



Arrange 154 in the following manner



(1 + 4) - 5  =  5  -  5 =  0  Since 11 Divides 0  the number 154 is divisible by 11...



 Lets take second example.. Does 11 divides 2607 ?



Arrange the number in the following manner...



(2  +  0) - (6 + 7) = 2 - 13  =  -11


Since 11 divides -11  the number 2607 is divisible by 11...



Now lets take a  large number 3469917


Again arrange the number



(  3  +  6  +  9  +  7  )  -  (  4  +  9  +  1  )  =   ( 25 ) - ( 14 ) = 11  



Since 11 divides 11 the number 3469917 is divisible by 11....



Note : If 11 does not divides the result(11 in the above example) then your number is not divisible by 11..

Posted in: Division, Maths