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835 LearnersLast updated on August 5, 2025

The cube root of 40 is the value which, when multiplied by itself three times (cubed), gives the original number 40. The cube root of 40 is 3.41995189335. The cube root of 40 is expressed as ∛40 in radical form, where the “ ∛ ” sign” is called the “radical” sign. In exponential form, it is written as (40)⅓. If “m” is the cube root of 40, then, m3=40. Let us find the value of “m”.
We can find cube root of 40 through a method, named as, Halley’s Method. Let us see how it finds the result.
Now, what is Halley’s Method? It is an iterative method for finding cube roots of a given number N, such that, x3=N, where this method approximates the value of “x”.
Formula is ∛a≅ x((x3+2a) / (2x3+a)), where
a=given number whose cube root you are going to find
x=integer guess for the cubic root
Let us apply Halley’s method on the given number 48.
Step 1: Let a=40. Let us take x as 3, since, 33=27 is the nearest perfect cube which is less than 40.
Step 2: Apply the formula. ∛40≅ 3((33+2×40) / (2(3)3+40))= 3.41…
Hence, 3.41… is the approximate cubic root of 40.


Understanding common misconceptions or mistakes can make your calculations error free. So let us see how to avoid those from happening.
Find ((∛80/ ∛40) × (∛80/ ∛40) × (∛80/ ∛40))
(∛80/ ∛40) × (∛80/ ∛40) × (∛80/ ∛40)
= (∛80× ∛80× ∛80) / (∛40× ∛40× ∛40)
=((80)⅓)3/ ((40)⅓)3
=80/40
=2
Answer: 2
We solved and simplified the exponent part first using the fact that, ∛80=(80)⅓ and ∛40=(40)⅓ , then solved.
If y = ∛40, find y³/ y⁶
Solution: y=∛40
⇒ y3/y6= (∛40)3 / (∛40)6
⇒ y3/y6= 40/ (40)2= 1/40
Answer: 1/40
(∛40)3=(401/3)3=40, and ∛(40)6=(401/3)6=(40)2. Using this, we found the value of y3/y6.
Multiply ∛40 × ∛64 × ∛125
∛40 × ∛64 × ∛125
= 3.41 × 4 ×5
= 68.2
Answer: 68.2
We know that the cubic root of 64 is 4 and the cubic root of 125 is 5, hence multiplying ∛125, ∛64 and ∛48.
What is ∛(100)⁶+ ∛(40)⁶ ?
∛(1006)+ ∛(40)6
= ((100)6))1/3 +((40)6)1/3
=(100)2 + (40)2= 10000 + 1600
Answer: 11600
We solved and simplified the exponent part first using the fact that, ∛100=(100)⅓ and ∛40=(40)⅓ , then solved.
Find ∛(40+(-8)+(-5)).
∛(40-8-5)
= ∛27
=3
Answer: 3
Simplified the expression, and found out the cubic root of the result.
1) The cube root of all odd numbers is an odd number. The same applies for even numbers also, that is, the cube of any even number is even.
2) The cube root of a negative number is also negative.
3) If the cube root of a number is a whole number, then that original number is said to be perfect cube

Vikrant is a passionate Mathematics teacher with over 5 years of teaching experience in both conventional and Vedic Maths. His student-focused approach combines clear concepts with motivation and encouragement, helping students build confidence and develo
: He loves to play the quiz with kids through algebra to make kids love it.
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