Here are the results for each of the additions:

1. 65520 + 2520 = 68040
2. 18.48 + 2.31 = 20.79
3. 129.68 + 16.21 = 145.89
4. 10349.15 + 796.10 = 11145.25
5. 5012.15 + 385.55 = 5397.70
6. 4471.48 + 343.96 = 4815.44
7. 41.0984 + 5.1373 = 46.2357

Would you like more details or have any questions?

Related Questions:

1. How to perform addition with decimals?
2. What are some tips for adding large numbers quickly?
3. How to estimate sums to check your work?
4. How do different rounding methods affect addition?
5. What are some common mistakes to avoid when adding decimals?

Tip: When adding numbers with decimals, align the decimal points to ensure accuracy.