find the cube root of 4913 , 12167,32768 by estimation
The cube root of 4913 has to be calculated.
We will make groups of three digits starting from the rightmost digit of 4913, as
. The groups are 4 and 913.
Considering the group 913,
The number 913 ends with 3. We know that if the digit 3 is at the end of a perfect cube number, then its cube root will have its unit place digit as 7 only. Therefore, the unit place digit of the required cube root is taken as 7.
Taking the other group i.e., 4,
We know that, 13 = 1 and 23 = 8
Also, 1 < 4 < 8
Therefore, 1 will be taken at the tens place of the required cube root.
Thus, 
The cube root of 12167 has to be calculated.
We will make groups of three digits starting from the rightmost digit of the number 12167, as
. The groups are 12 and 167.
Considering the group 167,
167 ends with 7. We know that if the digit 7 is at the end of a perfect cube number, then its cube root will have its unit place digit as 3 only. Therefore, the unit place digit of the required cube root can be taken as 3.
Taking the other group i.e., 12,
We know that, 23 = 8 and 33 = 27
Also, 8 < 12 < 27
2 is smaller between 2 and 3. Therefore, 2 will be taken at the tens place of the required cube root.
Thus, 
The cube root of 32768 has to be calculated.
We will make groups of three digits starting from the rightmost digit of the number 32768, as 
.
Considering the group 768,
768 ends with 8. We know that if the digit 8 is at the end of a perfect cube number, then its cube root will have its unit place digit as 2 only. Therefore, the unit place digit of the required cube root will be taken as 2.
Taking the other group i.e., 32,
We know that, 33 = 27 and 43 = 64
Also, 27 < 32 < 64
3 is smaller between 3 and 4. Therefore, 3 will be taken at the tens place of the required cube root.
Thus, 