Add numbers in scientific notation

When the powers of 10 match, add or subtract the numbers in front. Then make sure the front number is between 1 and 10.

1. Add: (8.6 × 10⁸) + (4.8 × 10⁸). Write the answer in scientific notation, like 4.7 × 10^3.
2. Add: (1.9 × 10⁸) + (2.2 × 10⁸). Write the answer in scientific notation, like 4.7 × 10^3.
3. Add: (1 × 10⁷) + (2.8 × 10⁷). Write the answer in scientific notation, like 4.7 × 10^3.
4. Add: (1.8 × 10⁵) + (6 × 10⁵). Write the answer in scientific notation, like 4.7 × 10^3.
5. Add: (4.2 × 10²) + (7.6 × 10²). Write the answer in scientific notation, like 4.7 × 10^3.
6. Add: (8.5 × 10⁸) + (5.2 × 10⁸). Write the answer in scientific notation, like 4.7 × 10^3.
7. Add: (8.7 × 10⁵) + (3.2 × 10⁵). Write the answer in scientific notation, like 4.7 × 10^3.
8. Add: (3.2 × 10³) + (1.6 × 10³). Write the answer in scientific notation, like 4.7 × 10^3.
9. Add: (1.38 × 10⁸) + (6.43 × 10⁸). Write the answer in scientific notation, like 4.7 × 10^3.
10. Add: (6.5 × 10⁷) + (4.69 × 10⁷). Write the answer in scientific notation, like 4.7 × 10^3.
11. Add: (8.32 × 10¹⁰) + (5.01 × 10¹⁰). Write the answer in scientific notation, like 4.7 × 10^3.
12. Add: (7.79 × 10⁸) + (6 × 10⁸). Write the answer in scientific notation, like 4.7 × 10^3.
13. Add: (8.4 × 10⁹) + (7.44 × 10⁹). Write the answer in scientific notation, like 4.7 × 10^3.
14. Add: (3.37 × 10¹²) + (2.43 × 10¹²). Write the answer in scientific notation, like 4.7 × 10^3.
15. Add: (3.04 × 10⁶) + (5.16 × 10⁶). Write the answer in scientific notation, like 4.7 × 10^3.
16. Add: (3.48 × 10⁴) + (4.29 × 10⁴). Write the answer in scientific notation, like 4.7 × 10^3.
17. Add: (2.7 × 10⁴) + (4.04 × 10⁴). Write the answer in scientific notation, like 4.7 × 10^3.
18. Add: (2.58 × 10³) + (3.77 × 10³). Write the answer in scientific notation, like 4.7 × 10^3.
19. Add: (4.67 × 10⁸) + (2.27 × 10⁸). Write the answer in scientific notation, like 4.7 × 10^3.
20. Add: (2.08 × 10⁷) + (4.22 × 10⁷). Write the answer in scientific notation, like 4.7 × 10^3.