1. 直接写出得数。
2.6 - 1.7 = 0.14 ÷ 0.07 = 72 ÷ 0.9 = 45 - 4.5 × 0.1 =
6.4 ÷ 4 = 8.5 + 85 = 1.43 + 2.6 = 40 ÷ 0.5 ÷ 0.1 =
1 - 0.93 = 20 × 6.5 = 200 × 4.5 = （1 + 0.3）× 0.3 =
0.5 × 0.6 = 8.5 ÷ 17 = 1.25 ÷ 0.25 = 0.3 × 0.5 ÷ 3 =
1.1 × 0.7 = 19 + 1.91 = 12.6 × 3 = 1 ÷ 0.1 × 2.3 =
8.5 × 0.2 = 0.87 - 0.8 = 44.1 - 4.2 = 3.5 + 3.5 ÷ 7 =
9.8 - 0.98 = 3.6 × 40 = 10.65 ÷ 0.5 = 5.3 - 4.2 + 0.7 =
0.93 ÷ 0.31 = 0.71 + 0.09 = 0.31 × 0.3 = 4.5 ×（4.8 ÷ 0.6）=

1. 0.9 2 80 44.55 1.6 93.5 4.03 800 0.07 130 900 0.39 0.3 0.5 5 0.05 0.77 20.91 37.8 23 1.7 0.07 39.9 4 8.82 144 21.3 1.8 3 0.8 0.093 36

2. 解方程。
x - 0.8x = 12 0.2x + 1.5 = 4 x ÷（20 - 10.5）= 41.8
1.4x + 1.2x = 5.2 6（x - 3.5）= 30 5x - 2.4 × 3 = 14.4

2. $ x = 60 $ $ x = 12.5 $ $ x = 397.1 $ $ x = 2 $ $ x = 8.5 $ $ x = 4.32 $

已知 A、B、C 是三个不同的质数，且 A + B + C = 48，则 A × B × C 的值最小是多少？最大是多少？

思维提升
$ 48 - 2 = 46 $ $ 46 = 3 + 43 = 5 + 41 = 17 + 29 $ 最小：$ 2 × 3 × 43 = 258 $ 最大：$ 2 × 17 × 29 = 986 $