Last updated on June 10th, 2025
When a number is multiplied by itself thrice, the resultant number is called the cube of a number. Cubing is used when comparing sizes of objects or things with cubic measurements. In this topic, we shall learn about the cube of 921.
A cube number is a value obtained by raising a number to the power of 3, or by multiplying the number by itself three times. When you cube a positive number, the result is always positive. When you cube a negative number, the result is always negative. This is because a negative number cubed results in a negative number.
The cube of 921 can be written as 921³, which is the exponential form. Or it can also be written in arithmetic form as 921 × 921 × 921.
Struggling with Math?
Get 1:1 Coaching to Boost Grades Fast !
To check whether a number is a cube number or not, we can use the following three methods: the multiplication method, a factor formula (a³), or by using a calculator. These three methods will help you cube numbers faster and easier without feeling confused or stuck while evaluating the answers.
The multiplication method is a process in mathematics used to find the product of two numbers or quantities by combining them through repeated addition. It is a fundamental operation that forms the basis for more complex mathematical concepts.
Step 1: Write down the cube of the given number. 921³ = 921 × 921 × 921
Step 2: Calculate the result. Hence, the cube of 921 is 780,748,641.
The formula (a + b)³ is a binomial formula for finding the cube of a number. The formula is expanded as a³ + 3a²b + 3ab² + b³.
Step 1: Split the number 921 into two parts. Let a = 900 and b = 21, so a + b = 921
Step 2: Now, apply the formula (a + b)³ = a³ + 3a²b + 3ab² + b³
Step 3: Calculate each term
a³ = 900³
3a²b = 3 × 900² × 21
3ab² = 3 × 900 × 21²
b³ = 21³
Step 4: Add all the terms together:
(a + b)³ = a³ + 3a²b + 3ab² + b³
(900 + 21)³ = 900³ + 3 × 900² × 21 + 3 × 900 × 21² + 21³
921³ = 729,000,000 + 510,300 + 3,969 + 9,261
921³ = 780,748,641
Step 5: Hence, the cube of 921 is 780,748,641.
To find the cube of 921 using a calculator, input the number 921 and use the cube function (if available) or multiply 921 × 921 × 921. This operation calculates the value of 921³, resulting in 780,748,641. It’s a quick way to determine the cube without manual computation.
Step 1: Ensure the calculator is functioning properly.
Step 2: Press 9 followed by 2 and 1.
Step 3: If the calculator has a cube function, press it to calculate 921³.
Step 4: If there is no cube function on the calculator, simply multiply 921 three times manually.
Step 5: The calculator will display 780,748,641.
There are some typical errors that might occur during the process of cubing a number. Let us take a look at five of the major mistakes that might occur:
Level Up with a Math Certification!
2X Faster Learning (Grades 1-12)
What is the cube and cube root of 921?
The cube of 921 is 780,748,641 and the cube root of 921 is approximately 9.733.
First, let’s find the cube of 921.
We know that the cube of a number is such that x³ = y, where x is the given number, and y is the cubed value of that number.
So, we get 921³ = 780,748,641.
Next, we must find the cube root of 921.
We know that the cube root of a number x is such that ∛x = y, where x is the given number, and y is the cube root value of the number.
So, we get ∛921 ≈ 9.733.
Hence, the cube of 921 is 780,748,641 and the cube root of 921 is approximately 9.733.
If the side length of a cube is 921 cm, what is the volume?
The volume is 780,748,641 cm³.
Use the volume formula for a cube V = Side³.
Substitute 921 for the side length: V = 921³ = 780,748,641 cm³.
How much larger is 921³ than 900³?
921³ – 900³ = 51,748,641.
First find the cube of 921, which is 780,748,641.
Next, find the cube of 900, which is 729,000,000.
Now, find the difference between them using the subtraction method.
780,748,641 – 729,000,000 = 51,748,641.
Therefore, 921³ is 51,748,641 larger than 900³.
If a cube with a side length of 921 cm is compared to a cube with a side length of 500 cm, how much larger is the volume of the larger cube?
The volume of the cube with a side length of 921 cm is 780,748,641 cm³.
To find its volume, multiply the side length by itself three times (since it’s a 3-dimensional object).
Cubing 921 means multiplying 921 by itself three times: 921 × 921 = 848,241, and then 848,241 × 921 = 780,748,641.
The unit of volume is cubic centimeters (cm³), because we are calculating the space inside the cube.
Therefore, the volume of the cube is 780,748,641 cm³.
Estimate the cube of 920 using the cube of 921.
The cube of 920 is approximately 780,748,641.
First, identify the cube of 921, The cube of 921 is 921³ = 780,748,641.
Since 920 is very close to 921, the cube of 920 will be very close to the cube of 921.
The cube of 920 is approximately 780,748,641 because the difference between 920 and 921 is very small.
So, we can approximate the value as 780,748,641.
Turn your child into a math star!
#1 Math Hack Schools Won't Teach!
Struggling with Math?
Get 1:1 Coaching to Boost Grades Fast !
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.