Question

How to find cube root by estimation method?

Answer 1

Find the cube root of -175616.

Solution :
We know that ∛-175616 = - ∛175616 

The number is even so its cube root has to an even number.

Make two groups ---> 175 616 

First group 616 ---> unit digit is 6 so unit digit of cube root will be 6 
(see the above table).

Second Group 175 -----> it lies between 53=125 and 63 = 216 .

So take the smaller number 5 as ten's place.