Last updated on May 30th, 2025
When a number is multiplied by itself three times, 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 9.
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 multiplied by itself three times results in a negative number.
The cube of 9 can be written as 9³, which is the exponential form. Or it can also be written in arithmetic form as 9 × 9 × 9.
To check whether a number is a cube number or not, we can use three methods: the multiplication method, a factor formula (a³), or by using a calculator. These methods help to cube numbers faster and easier without confusion. -
The multiplication method is a process in mathematics used to find the product of numbers 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. 9³ = 9 × 9 × 9
Step 2: You get 729 as the answer. Hence, the cube of 9 is 729.
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 9 into two parts. Let a = 5 and b = 4, so a + b = 9
Step 2: Now, apply the formula (a + b)³ = a³ + 3a²b + 3ab² + b³
Step 3: Calculate each term
a³ = 5³
3a²b = 3 × 5² × 4
3ab² = 3 × 5 × 4²
b³ = 4³
Step 4: Add all the terms together:
(a + b)³ = a³ + 3a²b + 3ab² + b³
(5 + 4)³ = 5³ + 3 × 5² × 4 + 3 × 5 × 4² + 4³
9³ = 125 + 300 + 240 + 64
9³ = 729
Step 5: Hence, the cube of 9 is 729.
To find the cube of 9 using a calculator, input the number 9 and use the cube function (if available) or multiply 9 × 9 × 9. This operation calculates the value of 9³, resulting in 729. It’s a quick way to determine the cube without manual computation.
Step 1: Ensure the calculator is functioning properly.
Step 2: Press 9
Step 3: If the calculator has a cube function, press it to calculate 9³.
Step 4: If there is no cube function on the calculator, simply multiply 9 three times manually.
Step 5: The calculator will display 729.
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 9?
The cube of 9 is 729 and the cube root of 9 is approximately 2.08.
First, let’s find the cube of 9.
We know that the cube of a number is x³ = y, where x is the given number, and y is the cubed value of that number.
So, we get 9³ = 729. Next, we must find the cube root of 9. We know that the cube root of a number x is ∛x = y, where x is the given number, and y is the cube root value of the number.
So, we get ∛9 ≈ 2.08.
Hence, the cube of 9 is 729 and the cube root of 9 is approximately 2.08.
If the side length of the cube is 9 cm, what is the volume?
The volume is 729 cm³.
Use the volume formula for a cube V = Side³.
Substitute 9 for the side length: V = 9³ = 729 cm³.
How much larger is 9³ than 4³?
9³ – 4³ = 665.
First, find the cube of 9³, which is 729.
Next, find the cube of 4³, which is 64.
Now, find the difference between them using the subtraction method.
729 – 64 = 665.
Therefore, 9³ is 665 larger than 4³.
If a cube with a side length of 9 cm is compared to a cube with a side length of 3 cm, how much larger is the volume of the larger cube?
The volume of the cube with a side length of 9 cm is 729 cm³.
To find its volume, we multiply the side length by itself three times (since it’s a 3-dimensional object).
Cubing 9 means multiplying 9 by itself three times: 9 × 9 = 81, and then 81 × 9 = 729.
The unit of volume is cubic centimeters (cm³) because we are calculating the space inside the cube.
Therefore, the volume of the cube is 729 cm³.
Estimate the cube 8.9 using the cube of 9.
The cube of 8.9 is approximately 729.
First, identify the cube of 9.
The cube of 9 is 9³ = 729. Since 8.9 is only a tiny bit less than 9, the cube of 8.9 will be almost the same as the cube of 9.
The cube of 8.9 is approximately 729 because the difference between 8.9 and 9 is very small.
So, we can approximate the value as 729.
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.