Cubes & cube roots
Cube numbers as real cubes, and finding the side again.
Learn with Kutty
Go one screen at a time. Press Next when you are ready. Tap 🔊 Read to me to listen.
A cube number makes a cube of blocks. The cube root is the side.
Look: 3 layers of 3 × 3: 27 small cubes.
✏️ Your turn!
Type your answer and press Check. Kutty will tell you if it is right.
15³ = ?
2∛1000 = ?
3∛64 = ?
! Careful!
✗3³ = 9.
✓3³ = 3 × 3 × 3 = 27.
✗Pairing primes for a cube root.
✓Group in threes.
See the whole lesson on one page
A cube number makes a cube of blocks. The cube root is the side.
3³ = 3 × 3 × 3 = 27, so ∛27 = 3. For big numbers, break into primes and group them in threes.
Think of it like thisA Rubik’s cube is 3 blocks long, 3 wide and 3 high: 27 small cubes. 27 = 3³.
Solved together
Find ∛2744.
Break into primes.
2 × 2 × 2 × 7 × 7 × 7Group in threes. Take one from each group.
2 × 7 = 14
Answer∛2744 = 14.
Now practise it
Kanakku makes new questions on cubes & cube roots every time. It shows the working and gives a hint when you are stuck.