The worksheet you have uploaded contains simple addition problems. Let me solve them for you:

1. $10 + 3 = 13$
2. $11 + 6 = 17$
3. $15 + 7 = 22$
4. $12 + 9 = 21$
5. $16 + 8 = 24$
6. $17 + 6 = 23$
7. $18 + 7 = 25$
8. $27 + 2 = 29$
9. $21 + 6 = 27$
10. $23 + 4 = 27$
11. $24 + 2 = 26$
12. $23 + 5 = 28$
13. $22 + 7 = 29$
14. $26 + 2 = 28$
15. $23 + 6 = 29$
16. $25 + 5 = 30$

Would you like any details on these additions or have any questions?

Here are some related questions you might find useful to expand your understanding:

1. What is the strategy to mentally add two numbers quickly?
2. Can you explain how carrying works when adding larger numbers?
3. How can practicing addition help with subtraction problems?
4. How does addition relate to multiplication?
5. What are the properties of addition (commutative, associative, etc.)?

Tip: When adding numbers mentally, grouping them into tens and smaller units can make the process faster.