Cube Root Examples with Solutions for Students (8th Grade Math)

📚 Quick Study Guide

• 🧊 Definition: The cube root of a number 'x' is a value 'y' such that $y^3 = x$. In simpler terms, it's the number that, when multiplied by itself three times, equals 'x'.
• ➗ Symbol: The cube root symbol is $\sqrt[3]{x}$, where 'x' is the number you're finding the cube root of.
• ➕ Perfect Cubes: Familiarize yourself with perfect cubes. Some common ones are: $1^3 = 1$, $2^3 = 8$, $3^3 = 27$, $4^3 = 64$, $5^3 = 125$, $6^3 = 216$, $7^3 = 343$, $8^3 = 512$, $9^3 = 729$, $10^3 = 1000$.
• ➖ Negative Numbers: Unlike square roots, you *can* find the cube root of a negative number. For example, the cube root of -8 is -2 because $(-2) \times (-2) \times (-2) = -8$.
• 💡 Estimation: If the number isn't a perfect cube, estimate the cube root by finding the perfect cubes it lies between.

Practice Quiz

1. What is the cube root of 27?
1. 3
2. 9
3. 6
4. 1
2. What is the cube root of -64?
1. 4
2. -4
3. 8
4. -8
3. What is the cube root of 125?
1. 5
2. 25
3. 10
4. 15
4. What is the cube root of 8?
1. 4
2. 2
3. 1
4. 3
5. What is the cube root of 1000?
1. 100
2. 10
3. 50
4. 20
6. What is the cube root of 0?
1. 1
2. -1
3. 0
4. undefined
7. Estimate the cube root of 30. Which whole number is closest?
1. 2
2. 4
3. 3
4. 5