What Is the Square Root of 64? A Simple Explanation

When learning about basic mathematics, one of the first questions students often ask is: What is the square root of 64? Understanding square roots is essential for algebra, geometry, and many real-world applications. In this article, we’ll break down what the square root of 64 is, why it matters, and how to calculate it—all in clear, easy-to-understand language.

What Is a Square Root?

Understanding the Context

The square root of a number is a value that, when multiplied by itself, gives the original number. For example, the square root of 16 is 4 because 4 × 4 = 16. The square root symbol is √, so √64 refers to the principal (non-negative) square root of 64.

What Is the Square Root of 64?

The square root of 64 is 8.

This is because:
8 × 8 = 64

Key Insights

So, √64 = 8.

It’s important to note that every positive number has two square roots: one positive (8) and one negative (−8), since both ×8 and ×(–8) yield 64. However, by convention, the square root symbol √ returns the original positive root—especially in basic math contexts. So when asked for the square root of 64, we say 8.

How to Calculate √64

You can find the square root of 64 in several ways:

1. By Factoring

We know 64 = 8 × 8, so √64 = 8.

Final Thoughts

2. Using a Calculator

Simply input “√64” on any scientific calculator to get the result instantly: √64 = 8.

3. Estimation and Rounding

If you don’t have a calculator, you can estimate:

  • 8² = 64 → so √64 = 8
  • 9² = 81 > 64, so the root must be less than 9
    Hence, the closest integer and exact value is 8.

Why Is the Square Root of 64 Important?

Understanding exact square roots like √64 builds a strong foundation in arithmetic and algebra. Square roots appear in various fields such as:

  • Geometry: Calculating the diagonal of a square (e.g., a square with side 8 units has a diagonal of 8√2, derived from √64 in related formulas).
  • Physics: Finding distances or scaling factors in equations.
  • Finance & Engineering: Simplifying complex formulas involving area and volume.

Moreover, knowing √64 = 8 helps improve mental math skills and prepares learners for radicals and irrational numbers.

Fun Facts About Square Roots

  • √64 is a whole number, making it a “nice” root often used in teaching.
  • Many perfect squares, including 64, 100, 144, and 256, have integer square roots.
  • In binary and computer science, understanding square roots supports algorithms involving powers and exponents.

Conclusion

The square root of 64 is 8—a simple but foundational mathematical truth. Whether you’re solving equations, designing structures, or expanding your STEM knowledge, mastering square roots starts here. Next time someone asks, What is the square root of 64?, you’ll confidently reply: Eight, and explain why that matters.