26-90. Perform the operations.

Solution:

1. \( 2.1 + 3.7 = 5.8 \)
2. \( 3.2 + 1.52 = 4.72 \)
3. \( 2.14 + 12.4 = 14.54 \)
4. \( 2.8 + 13.68 + 4.12 = 20.6 \)
5. \( 1.23 + 2.145 + 11.2 = 14.575 \)
6. \( 3.21 - 2.02 = 1.19 \)
7. \( 2.84 - 1.2 = 1.64 \)
8. \( 8.7 - 1.96 = 6.74 \)
9. \( 3.2 - 1.54 + 1.2 = 2.86 \)
10. \( 3 - 1.124 + 3.14 = 4.016 \)
11. \( 1.2 \times 15 = 18 \)
12. \( 3.2 \times 17 = 54.4 \)

Answer: 26. 5.8; 27. 4.72; 28. 14.54; 29. 20.6; 30. 14.575; 31. 1.19; 32. 1.64; 33. 6.74; 34. 2.86; 35. 4.016; 36. 18; 37. 54.4.