Sure! Here’s how you can make 10 using the numbers 1, 1, 9, and 9 with the allowed operations:

$(9 \div 9) + (1 + 1) = 1 + 2 = 10$

This is a valid solution using each number once and applying the operations correctly.

Would you like to see other possible solutions or more details? Let me know if you'd like help with any part of it!

Here are some related questions for practice:

1. How can you make 12 using the numbers 1, 1, 9, 9?
2. What are some strategies for combining numbers to reach a target number?
3. How can the distributive property help in combining numbers with different operations?
4. How would you make 7 using only the numbers 2, 3, 5, and 8?
5. Can you find a way to make 10 using only subtraction and division?

Tip: When combining numbers to reach a target, always start by experimenting with division to simplify large numbers before using addition or subtraction.