Cube Root - Definition, Examples, Quiz, FAQ, Trivia

What is a Cube Root?

A cube root is a special number that, when multiplied by itself three times, gives the original number.

Think about building a cube with small blocks. If you have 8 small blocks, you can build a 2x2x2 cube. So the cube root of 8 is 2. If you have 27 blocks, you can build a 3x3x3 cube, so the cube root of 27 is 3.

Example: What's the cube root of 125? It's 5 because 5 × 5 × 5 = 125.

Cube Root Symbol

The cube root symbol looks like this: ∛

It's a special symbol that means "cube root." You write it before a number to show you're finding its cube root.

Examples:
∛8 = 2 (because 2 × 2 × 2 = 8)
∛27 = 3 (because 3 × 3 × 3 = 27)
∛64 = 4 (because 4 × 4 × 4 = 64)

The small 3 in the symbol tells us we're finding the cube root, not the square root.

How to Find Cube Roots

Finding cube roots is easier when you know some perfect cubes. Here's how to do it:

Step 1: Learn the first few perfect cubes:

• 1³ = 1 × 1 × 1 = 1
• 2³ = 2 × 2 × 2 = 8
• 3³ = 3 × 3 × 3 = 27
• 4³ = 4 × 4 × 4 = 64
• 5³ = 5 × 5 × 5 = 125
• 6³ = 6 × 6 × 6 = 216
• 7³ = 7 × 7 × 7 = 343
• 8³ = 8 × 8 × 8 = 512
• 9³ = 9 × 9 × 9 = 729
• 10³ = 10 × 10 × 10 = 1000

Cube Root Examples

Let's look at some common cube roots:

Cube Root Practice Quiz

Test your understanding with these practice questions. Choose the correct answer for each.

Frequently Asked Questions

Here are answers to common questions about cube roots:

Math Trivia

Discover interesting facts about cube roots and mathematics: