how to find cube root of 1953125 by the method of estimation? it has 3 groups

1 953  125

Make three groups:

first group = 125 

the no. ends up with 5. therefore, if the digit 5 is at the end of a perfect cube no, then its cube root is taken 5 as the unit place.

Now, 

second group = 953

8*8*8=512

and 1000=10*10*10

so 

512<953<1000

8³<953<10³

therefore, 8 is taken at the tens place.

third group = 1

thus, the cube root of 1953125(estimation)= 185