Question

in estimation method for finding cube root if the second group is a perfect cube then what should we do

Answer 1

Answer:

Finding cube root by estimation

Make group of 3 digit, starting from right.

The unit digit of cube root will be. Unit digit of cube root of 857375 = Unit digit of cube root of 375. Since 375 ends in 5, it's cube root will end in 5. (As 5 3 = 12 5 , 1 5 3 = 337 5 )

Now, for second group. 8 5 7. We note that. 9 3 = 729. first group is 375 second group is 857