The question is asking you to approximate the square root of 78 using perfect squares. Let's break down the steps:

1. Identify two perfect squares between which $\sqrt{78}$ lies.

   • The perfect squares near 78 are $64$ (since $\sqrt{64} = 8$) and $81$ (since $\sqrt{81} = 9$).
   • So, $\sqrt{64} < \sqrt{78} < \sqrt{81}$.

2. Therefore, $\sqrt{78}$ is between 8 and 9.

Here is how the blanks should be filled in:

• $8 < \sqrt{78} < 9$

To complete the final sentence:

• $\sqrt{78}$ is between 8 and 9.

Would you like more details or have any questions about these steps?

Here are five related questions to further your understanding:

1. How would you approximate $\sqrt{50}$ using perfect squares?
2. What is the process of estimating $\sqrt{150}$?
3. Can you find two perfect squares between which $\sqrt{120}$ lies?
4. How can you get a better approximation of $\sqrt{78}$ beyond using perfect squares?
5. What are the steps for estimating cube roots similarly to square roots?

Tip: When estimating square roots, remember that perfect squares are numbers like 1, 4, 9, 16, 25, etc., and help you approximate values for non-perfect squares.