The expression in the image is the cube root of 64, written as:

$\sqrt[3]{64}$

The cube root of 64 is the number that, when multiplied by itself three times, gives 64. We can calculate this as:

$\sqrt[3]{64} = 4$

Since $4 \times 4 \times 4 = 64$.

Would you like more details on cube roots or have any further questions? Here are some related questions you may find useful:

1. How do you calculate higher-order roots, such as the fourth root of a number?
2. Can negative numbers have cube roots, and how do we calculate them?
3. What is the relationship between exponents and roots in mathematics?
4. How do cube roots apply in real-world problems like volume calculations?
5. How can you approximate cube roots of non-perfect cubes?

Tip: Cube roots can be calculated easily using a scientific calculator or by recognizing the cube of small integers like 2, 3, 4, etc.