TO FIND CUBE ROOTS OF PERFECT CUBE NUMBERS IN 10 SECONDS

To find cube roots of perfect cube numbers in 10 seconds

Learn first ten cubes:

1³=1   2³=8    3³=27    4³=64    5³=125    6³=216    7³=343    8³=512  9³=729    

10³=1000

Q.1Now  let us find cube root of 1728

Solution:- 1,728 (make groups of three starting from units place)

 Here the last digit is 8.Cube of 8 ends in 2 so write 2 on units place.The highest number whose cube  can be subtracted from next group 1 so that the result is positive is 1 so tens digit will be 1.so ans is 12

Q.2 Find cube root of 614125

Solution:- 614,125 (make groups of three starting from units place)

Here the last digit is 5.Cube of 5 ends in 5 so write 5 on units place.The highest  number whose cube  can be subtracted from next group 614 so that the result is positive is 8 so write 8 on tens place .so ans is 85

Similarly cube root of:-

970299 is 99       

 912673 is 97

 250047 is 63

157464 is 54

110592 is 48