Answer:
1. 0.92 rounds to 0.90 and 5.37 rounds to 5.40 (0.9 + 5.4 = 6.3)
2. 6.3 rounds to 6 and 2.8 rounds to 3 (6 - 3 = 3)
3. 13.56 rounds to 13.60 and 10.02 rounds to 10 (13.6 - 10 = 3.6)
4. 7.032 + 2.485 + 4.59 = 14.107
5. 57.403 - 55.78 = 1.623
6. 13.46 rounds to 13.50, 7.84 rounds to 7.80 and 2.59 rounds to 2.60 (13.5 + 7.8 + 2.6 = 23.9)
7. 1,472.63 rounds to 1,473 and 975.28 rounds to 975(1,473 - 975 = 498)
8. 38.24 rounds to 38, 14.53 rounds to 15 and 8.93 rounds to 9(38 + 15 + 9 = 62)
9. 16.4 rounds to 16 and 12.8 rounds to 13(16 + 13 = 29)
(some may be wrong but i did my best)