Find the cube root of each of the following numbers:
(i) (ii)
(iii) (iv)
(i) We know that for any two integers a and b,
So from this property, we have:
(ii) By Applying a and b, , we have
To find out cube root by using units digit:
Let’s take the number 1728.
So,
Unit digit = 8
The unit digit in the cube root of 1728 = 2
After striking out the units, tens and hundreds digits of the given number, we are left with the 1.
As we know 1 is the largest number whose cube is less than or equals to 1.
So,
The tens digit of the cube root of 1728 = 1
Prime factors of 216 = 2×2×2×3×3×3
On grouping the factors in triples of equal factor,
We have,
216 = {2×2×2}×{3×3×3}
Taking one factor from each group we get,
So,
(iii) By Applying a and b propertise, , we have
To find out cube root by using units digit:
Let’s take the number 2744.
So,
Unit digit = 4
The unit digit in the cube root of 2744= 4
After striking out the units, tens and hundreds digits of the given number, we are left with the 2.
As we know 1 is the largest number whose cube is less than or equals to 2.
So,
The tens digit of the cube root of 2744 = 1
Prime factors of 216 = 2×2×2×3×3×3
On grouping the factors in triples of equal factor,
We have,
216 = {2×2×2}×{3×3×3}
Taking one factor from each group we get,
So,
(iv) By Applying a and b propertise,, we have
To find out cube root by using units digit:
Let’s take the number 15625.
So,
Unit digit = 5
The unit digit in the cube root of 15625 = 5
After striking out the units, tens and hundreds digits of the given number, we are left with the 15.
As we know 2 is the largest number whose cube is less than or equals to 15(23<15<33).
So,
The tens digit of the cube root of 15625 = 2
Also
As we know 9×9×9 = 729
Thus,