Question

Find the cube root of the following perfect cubes by estimation method :- 1) 68921 2) 205379 3) 373248 4) 21952 5) 25004

Answer 1

Answer:

Hello daksh its manav in your school class 8P

I already did these sums

Step-by-step explanation:

1) 68921

First separate the number

= 68 921

unit digit number units digit number(cube)

1 1

2 8

3 7

4 4

5 5

6 6

7 3

8 2

9 9

0 0

U need to know these units digit of cube

921 has units digit 1

So unit digit is 1

68 lies between 4^3 and 5^3 that is 64 and 125

Take smallest number (from 4 and 5) that is 4

So tens digit = 4

Therefore Cube root of 68921 is 41

2) 205379

205 379

379 has unit digit 9

So unit digit of number is 9

205 lies between 5^3 and 6^3

So tens digit is 5

Cube root of 205379 is 59

3) 373248

373 248

248 has unit digit 8

So unit digit is 2

373 lies between 7^3 and 8^3

So tens digit is 7

Cube root of 373248 is 72

4) 21952

21 952

952 has unit digit 2

So units digit is 8

21 lies between 2^3 and 3^3

So tens digit is 2

Cube root of 21952 is 28

5) Daksh actually that is 250047 not 25004

250 047

047 has unit digit 7

So units digit is 3

250 lies between 6^3 and 7^3

So tens digit is 6

Cube root of 250047 is 63

Daksh I did these all by estimation method

Please mark me as the brainliest answer

Thank you ☺