Summarize this article:
554 LearnersLast updated on August 5, 2025

The cube root of 243 is the value that, when multiplied by itself three times (cubed), gives the original number 243. Do you know? Cube roots apply to our real life also, like that for measuring dimensions, designing structures, density and mass, field of engineering etc.
The cube root of 243 is 6.24025146916. The cube root of 243 is expressed as โ243 in radical form, where the “ โ “ sign is called the “radical” sign. In exponential form, it is written as (243)1/3. If “m” is the cube root of 243, then, m3=243. Let us find the value of “m”.
The cube root of 243 is expressed as 3โ9 as its simplest radical form, since
243 = 3×3×3×3×3
โ243 = โ(3×3×3×3×3)
Group together three same factors at a time and put the remaining factor under โ .
โ243= 3โ9
We can find cube root of 243 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 โa≅ 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 243.
Step 1: Let a=243. Let us take x as 6, since, 63=216 is the nearest perfect cube which is less than 243.
Step 2: Apply the formula. โ243≅ 6((63+2×243) / (2(6)3+243))= 6.24
Hence, 6.24 is the approximate cubic root of 243.
some common mistakes and solutions are given below:
Find (โ240/ โ243) ร (โ241/ โ243) ร (โ242/ โ243)
(โ240/ โ243) × (โ241/ โ243) × (โ242/ โ243)
= (โ240× โ241× โ242) / (โ243× โ243× โ243)
=(โ240× โ241× โ242)/ ((243)โ
)3
=(โ240× โ241× โ242)/243
=(6.214 × 6.223 × 6.231)/ 243
Answer: (6.214 × 6.223 × 6.231)/ 243
We used the fact that ((243)โ
)3=243 and then found the cube roots of 240,241, and 242 and simplified.
The length, breadth, and height of a cuboid is 5 unit, 4 unit, and 4.5 cm respectively. To find its volume, also find the measure of a side of a cube, whose volume is 243 cubic units.
Volume of a cuboid = length × breadth × height = 5 × 4 × 4.5 cubic units = 90 cubic units.
Given, Volume of a cube = 243 cubic units
⇒ side × side × side = 243 cubic units
⇒ side = โ243
⇒ side = 6.24 units
Answer: Volume of the cuboid = 90 cubic units
Side length of the cube = 6.24 units
Applied the formula and concept of the volume of a cuboid and cube and solved.
Multiply โ243 ร โ216
โ243×โ216
= 6.24×6
= 37.44
Answer: 37.44
We know that the cubic root of 216 is 6, hence multiplying โ216 with โ243.
What is โ(243โถ^1/6) ?
โ(2436×1/6)
= (243)1/3
= 6.24…
Answer: 6.24
We solved and simplified the exponent part first using the fact that, (2436×1/6)=243, then solved.
Find โ(243-(-100)).
โ(243-(-100))
= โ(243+100)
=โ343
=7
Answer: 7
Simplified the expression, and found out the cubic root of the result.
Jaskaran Singh Saluja is a math wizard with nearly three years of experience as a math teacher. His expertise is in algebra, so he can make algebra classes interesting by turning tricky equations into simple puzzles.
: He loves to play the quiz with kids through algebra to make kids love it.






