The expression $\sqrt{\sqrt{4}}$ can be simplified as follows:

1. First, calculate $\sqrt{4}$: $\sqrt{4} = 2$

2. Now, take the square root of the result: $\sqrt{2} \approx 1.414$

So, $\sqrt{\sqrt{4}} \approx 1.414$.

Would you like a more detailed explanation or have any other questions?

Here are some related questions:

1. What is the general rule for simplifying nested square roots?
2. How do you simplify $\sqrt{\sqrt{16}}$?
3. What is the square root of non-perfect square numbers?
4. How is $\sqrt{2}$ used in geometry or trigonometry?
5. How do you handle cube roots within square roots?

Tip: Nested square roots often require simplifying step-by-step, starting from the innermost expression.