Last updated on May 28th, 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 cubes of 3.
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 by itself three times results in a negative number.
The cube of 3 can be written as 3³, which is the exponential form.
Or it can also be written in arithmetic form as 3 × 3 × 3.
In order to check whether a number is a cube number or not, we can use the following three methods, such as the multiplication method, a factor formula (a³), or by using a calculator. These three methods will help kids to cube the 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. 3³ = 3 × 3 × 3
Step 2: You get 27 as the answer.
Hence, the cube of 3 is 27.
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 3 into two parts, as 2 and 1. Let a = 2 and b = 1, so a + b = 3
Step 2: Now, apply the formula (a + b)³ = a³ + 3a²b + 3ab² + b³
Step 3: Calculate each term a³ = 2³ 3a²b = 3 × 2² × 1 3ab² = 3 × 2 × 1² b³ = 1³
Step 4: Add all the terms together: (a + b)³ = a³ + 3a²b + 3ab² + b³ (2 + 1)³ = 2³ + 3 × 2² × 1 + 3 × 2 × 1² + 1³ 3³ = 8 + 12 + 6 + 1 3³ = 27
Step 5: Hence, the cube of 3 is 27.
To find the cube of 3 using a calculator, input the number 3 and use the cube function (if available) or multiply 3 × 3 × 3. This operation calculates the value of 3³, resulting in 27. It’s a quick way to determine the cube without manual computation.
Step 1: Ensure the calculator is functioning properly.
Step 2: Press 3
Step 3: If the calculator has a cube function, press it to calculate 3³.
Step 4: If there is no cube function on the calculator, simply multiply 3 three times manually.
Step 5: The calculator will display 27.
There are some typical errors that kids might make during the process of cubing a number. Let us take a look at five of the major mistakes that kids might make:
What is the cube and cube root of 3?
The cube of 3 is 27 and the cube root of 3 is approximately 1.442.
First, let’s find the cube of 3.
We know that the cube of a number, such that x³ = y
Where x is the given number, and y is the cubed value of that number
So, we get 3³ = 27 Next, we must find the cube root of 3
We know that the cube root of a number ‘x’, such that ∛x = y
Where ‘x’ is the given number, and y is the cube root value of the number
So, we get ∛3 ≈ 1.442
Hence the cube of 3 is 27 and the cube root of 3 is approximately 1.442.
If the side length of the cube is 3 cm, what is the volume?
The volume is 27 cm³.
Use the volume formula for a cube V = Side³.
Substitute 3 for the side length: V = 3³ = 27 cm³.
How much larger is 3³ than 2³?
3³ – 2³ = 19.
First find the cube of 3³, that is 27
Next, find the cube of 2³, which is 8
Now, find the difference between them using the subtraction method. 27 – 8 = 19
Therefore, 3³ is 19 larger than 2³.
If a cube with a side length of 3 cm is compared to a cube with a side length of 1 cm, how much larger is the volume of the larger cube?
The volume of the cube with a side length of 3 cm is 27 cm³.
To find its volume, we multiply the side length by itself three times (since it’s a 3-dimensional object).
Cubing 3 means multiplying 3 by itself three times: 3 × 3 = 9, and then 9 × 3 = 27.
The unit of volume is cubic centimeters (cm³) because we are calculating the space inside the cube.
Therefore, the volume of the cube is 27 cm³.
Estimate the cube of 2.9 using the cube of 3.
The cube of 2.9 is approximately 24.389.
First, identify the cube of 3,
The cube of 3 is 3³ = 27.
Since 2.9 is only a tiny bit less than 3, the cube of 2.9 will be slightly less than the cube of 3.
Calculate the cube of 2.9: 2.9 × 2.9 × 2.9 ≈ 24.389.
So, the cube of 2.9 is approximately 24.389, slightly less than 27.
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.