SEAGReady
NumberP6 level16 questions in the full course

Cube NumbersSEAG Practice Questions

Understanding cube numbers as a number multiplied by itself three times (e.g., 3³ = 27), recognising cubes up to 5³ = 125.

Where your child meets this in real life: Calculating volumes of cubes, understanding 3D scaling

What your child needs to know

SEAGReady breaks cube numbers into 2 steps, taught in order so each skill builds on the last.

  1. 1

    Calculate Cube Numbers

    Calculate cube numbers from 1³ to 5³ by multiplying a number by itself three times

  2. 2

    Recognize Cube Numbers

    Identify cube numbers and find which number was cubed to produce a given cube number

Try these SEAG-style questions

Three free sample questions from our cube numbers course. Every question comes with a full explanation, and hints that guide without giving the answer away.

Question 1Confidence builder

Oisin is building a cube out of toy bricks. Each edge of his cube is 3 bricks long. How many toy bricks does he need altogether?

  • A27 bricks
  • B9 bricks
  • C6 bricks
  • D12 bricks
Show answer and explanation

Answer: A. 27 bricks

Each edge is 3 bricks long. 3 cubed means 3 x 3 x 3 Step 1: 3 x 3 = 9 Step 2: 9 x 3 = 27 Oisin needs 27 toy bricks.

Stuck? Start here: A cube has the same length, width, and height. How many bricks along each edge?

Question 2Confidence builder

Niamh sees these numbers on the whiteboard: 9, 27, 36. Her teacher says one of them is a cube number. Which number is it?

  • A27
  • B9
  • C36
  • DNone of them
Show answer and explanation

Answer: A. 27

The cube numbers from 1 to 5 are: 1³ = 1, 2³ = 8, 3³ = 27, 4³ = 64, 5³ = 125 Looking at 9, 27, 36: 27 is on the list (27 = 3³) 9 is a square number (3²), not a cube 36 is a square number (6²), not a cube Answer: 27 is the cube number.

Stuck? Start here: Cube numbers come from multiplying a number by itself three times

Question 3Confidence builder

What is 2 cubed (2³)?

  • A8
  • B6
  • C4
  • D9
Show answer and explanation

Answer: A. 8

2 cubed means 2 x 2 x 2 Step 1: 2 x 2 = 4 Step 2: 4 x 2 = 8 Answer: 2³ = 8

Stuck? Start here: The small 3 tells you how many times to multiply 2 by itself

Try the lesson: Calculate Cube Numbers

This is the exact interactive worked example your child sees in SEAGReady. Step through it and watch the method build up.

Ciara is building a cube out of small wooden blocks. Each edge of her cube is 4 blocks long.

How many small blocks does she need altogether?

Understand what cube means
1

4 cubed means 4 multiplied by itself 3 times

4³ = 4 × 4 × 4

Step 1 of 3

Prefer to read? See every step written out

Ciara is building a cube out of small wooden blocks. Each edge of her cube is 4 blocks long.

How many small blocks does she need altogether?

  1. 1

    Understand what cube means

    • 4 cubed means 4 multiplied by itself 3 times4³ = 4 × 4 × 4
  2. 2

    Multiply step by step

    • First multiply 4 by 44 × 4 = 16
    • Then multiply that result by 416 × 4 = 64

Ciara needs 64 small blocks to build her cube.

The key insight: Cubing is NOT the same as multiplying by 3. It means multiplying the number by itself THREE times!

Watch out: 4³ = 12 (thinking 4 × 3). The small 3 tells you HOW MANY times to multiply 4 by itself, not what to multiply 4 by.

Mistakes to watch for

These are the misconceptions we see most often in cube numbers, including the ones our practice questions are specifically designed to catch.

  • Confusing cube with square (3³ ≠ 9)
  • Thinking cube means multiply by 3 (3³ ≠ 9)
  • Not connecting to volume of cubes

Build these skills first

Struggling with cube numbers? The real gap is often in one of these earlier topics.

More number practice

16 questions on this topic alone

Master cube numbers and everything it unlocks

SEAGReady finds the exact step where your child gets stuck, teaches it with worked examples like the one above, and brings it back for review so it sticks.