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Maths Facts

Why cube numbers are called cube

Build cube stacks to show 1, 8, 27 and more.

Quick answer

Cube numbers are called "cube" because they can be built into perfect cubes using blocks or counters. When you make a cube with 1 block, 8 blocks, or 27 blocks, you're making a 1x1x1 cube, a 2x2x2 cube, or a 3x3x3 cube.

Learning outcome

By the end of this page, you will understand why cube numbers are called "cube" and be able to make cube numbers using blocks or drawings. Success signs:
  • You can build a 1x1x1 cube with 1 block
  • You can build a 2x2x2 cube with 8 blocks
  • You can build a 3x3x3 cube with 27 blocks
  • You can explain that cube numbers are 1, 8, 27, 64, 125, and so on

Why this matters

Understanding cube numbers helps you see how numbers work in 3D space. This idea is used in building, art, puzzles, and even in computer games where you make 3D shapes. Knowing cube numbers also helps with more advanced maths like volume, algebra, and patterns. When you understand cubes, you can see how numbers grow in a special way.

How it works

To make a cube number, you multiply a number by itself three times. This is called "cubing" the number. For example:
  • 1 cubed = 1 × 1 × 1 = 1
  • 2 cubed = 2 × 2 × 2 = 8
  • 3 cubed = 3 × 3 × 3 = 27
  • 4 cubed = 4 × 4 × 4 = 64
Each cube number can be built into a perfect cube shape using blocks or counters.

Examples you can see

Let's imagine you have small blocks you can stack to make cubes. 1 cube:
  • 1 block makes a 1x1x1 cube
  • This is 1 × 1 × 1 = 1 block
8 cubes:
  • 8 blocks make a 2x2x2 cube
  • That's 2 rows of 2 blocks, 2 layers high
  • 2 × 2 × 2 = 8 blocks
27 cubes:
  • 27 blocks make a 3x3x3 cube
  • 3 rows of 3 blocks, 3 layers high
  • 3 × 3 × 3 = 27 blocks
64 cubes:
  • 64 blocks make a 4x4x4 cube
  • 4 rows of 4 blocks, 4 layers high
  • 4 × 4 × 4 = 64 blocks

Try it as a mini adventure

Adventure: Build a Cube Kingdom! You are the builder of a magical kingdom where all buildings are cubes. Your job is to build different cube towers for the king. Step 1: Make a 1x1x1 cube tower with 1 block. Step 2: Make a 2x2x2 cube tower with 8 blocks. Step 3: Make a 3x3x3 cube tower with 27 blocks. Step 4: Make a 4x4x4 cube tower with 64 blocks. Step 5: Make a 5x5x5 cube tower with 125 blocks. Step 6: Count all the blocks you used to build your kingdom. Step 7: Draw your cube kingdom and label each tower with its cube number. Step 8: Ask a grown-up to help you write down all the cube numbers you made: 1, 8, 27, 64, 125.

Common mistakes

  • Mistake: Thinking 3 × 3 = 9, then 9 × 3 = 27, so 3 cubed = 27.
    Why it happens: Confusing multiplication with addition.
    Fix: Remember that 3 cubed means 3 × 3 × 3 = 27. The first 3 × 3 = 9, then multiply by 3 again to get 27.
  • Mistake: Counting blocks in the wrong way when making a cube.
    Why it happens: Not understanding that you need to make rows, columns, and layers.
    Fix: Start with one layer, then add more layers on top. Count carefully in groups.
  • Mistake: Thinking that 2 × 2 = 4, so 2 cubed = 4.
    Why it happens: Forgetting that cubing means multiplying by itself three times.
    Fix: Remember that 2 cubed = 2 × 2 × 2 = 8. Not just 2 × 2.

Parent and carer guide

You can help your child by:
  • Using small cubes or blocks to build the cubes together
  • Playing a counting game: "Let's make a 2x2x2 cube. How many blocks do we need?"
  • Using everyday objects like sugar cubes or dice to show cube numbers
  • Pointing out cube numbers in real life: dice are 6-sided cubes, sugar cubes are 1x1x1 cubes
  • Encouraging your child to draw their cube towers
  • Practising the multiplication facts: 1 × 1 × 1 = 1, 2 × 2 × 2 = 8, 3 × 3 × 3 = 27, etc.
If your child gets confused:
  • Start with smaller numbers like 1 and 2
  • Use physical blocks to show each step
  • Ask questions like "How many blocks are in one layer?" and "How many layers do we need?"
  • Remember that making mistakes is part of learning

Practice questions

  1. What is 1 cubed?
  2. What is 2 cubed?
  3. What is 3 cubed?
  4. What is 4 cubed?
  5. What is 5 cubed?
  6. What is 6 cubed?
  7. What is 7 cubed?
  8. What is 8 cubed?
  9. What is 9 cubed?
  10. What is 10 cubed?
Answers:
  1. 1 cubed = 1
  2. 2 cubed = 8
  3. 3 cubed = 27
  4. 4 cubed = 64
  5. 5 cubed = 125
  6. 6 cubed = 216
  7. 7 cubed = 343
  8. 8 cubed = 512
  9. 9 cubed = 729
  10. 10 cubed = 1000

FAQ

What is a cube number?

A cube number is a number that can be made by multiplying a number by itself three times. For example, 27 is a cube number because 3 × 3 × 3 = 27.

Why are they called cube numbers?

They are called cube numbers because they can be built into perfect cube shapes using blocks or counters. A 3x3x3 cube uses 27 blocks, which is 3 cubed.

What are the first few cube numbers?

The first few cube numbers are: 1, 8, 27, 64, 125, 216, 343, 512, 729, 1000.

How do I know if a number is a cube number?

If you can find a whole number that, when multiplied by itself three times, equals your number, then it's a cube number. For example, 64 is a cube number because 4 × 4 × 4 = 64.

Are there any real-life examples of cube numbers?

Yes! Dice are 6-sided cubes, sugar cubes are 1x1x1 cubes, and some boxes are 2x2x2 or 3x3x3 cubes. Cube numbers are also used in computer games and building blocks.