Question

Find the cube root of the following natural number 1728 .

Answer 1

Cube root using units digit:
Let us consider 1728.
The unit digit is 8; therefore, the unit digit in the cube root of 1728 is 2.
After striking out the units, tens and hundreds digits of the given number, we are left with 1.
Now, 1 is the largest number whose cube is less than or equal to 1.
Therefore, the tens digit of the cube root of 1728 is 1.
Hence, 

\[\sqrt[3]{1728} = 12\]