Question

find the cube root of 4 741632 by estimation

Answer 1

hello dear friend,

so, the no. you have got is 4741632.

okay first determine total digits  in the number, then start the estimation of grouping.

nos. 1 to 3 give us cubes of 1-digit.
then, nos. 4 gives us cubes of 2-digits
similarly, no. from 5 to 9 give us cube of 3-digits.
then, nos. from 10 to 21 give us cube of 4-digits.
& nos. from 22 to 46 give us  cube of 5-digits.
& nos. from 47 to 99 give us cube of 6-digits.
at last ,nos. from 100 to 215 give us cube of 7-digits.

so we can find that according to your question your number is a 7-digit no.

this means  it  is having the  cube root as a 3-digit number .

 the unit's digit is 2, and only the nos. ending  with 8 produce cubes ending with 2.

thus, the numbers can be either of from:

108, 118, 128, 138, 148, 158, 168, 178, 188, or 198.

the   number you want  is 4741632 ,

so if we collectively go to the middle nos, and not focus from first to last, we can calculate , the cube of 150 becomes 3375000  

& that of 160 is 4096000.

going on to 170 's cube is 4913000.(nearly close to  4741632)

by this u should opt for no. 168  which has nearly close to cube no. of  the given

and calculating: 168 x 168 x 168 = 4741632

hence , by estimation , the result is 168 (required answer)

hope this helps !! thanks & goodluck !!