1. 直接写出得数。
$325 - 305 =$
$0.45 ÷ 0.1 =$
$2.7 × 0.1 =$
$4.8 ÷ 0.6 - 3 =$
$1.2 × 0.3 =$
$125 - 65 =$
$1.2 ÷ 0.04 =$
$0.12 ÷ 0.03 ÷ 8 =$
$0.15 × 4 =$
$0.36 ÷ 0.06 =$
$3.25 - 0.1 =$
$1.6 - 1.6 ÷ 4 =$
$0.42 ÷ 0.02 =$
$1.3 + 0.7 =$
$0.013 ÷ 0.01 =$
$4.2 + 1.8 ÷ 2 =$
$15 ÷ \frac{5}{13} =$
$\frac{1}{50} × 25 =$
$\frac{5}{8} + 0.75 =$
$\frac{4}{9} + \frac{5}{9} ÷ 10 =$
$\frac{3}{4} ÷ 2.5 =$
$\frac{5}{7} ÷ \frac{3}{14} =$
$\frac{1}{20} × \frac{5}{6} =$
$\frac{4}{19} + 5 × \frac{2}{5} =$
$\frac{8}{25} ÷ \frac{6}{5} =$
$\frac{13}{15} × \frac{3}{4} =$
$12 ÷ \frac{4}{9} =$
$8 × \frac{1}{4} × \frac{2}{3} =$
$\frac{9}{8} × 7.2 =$
$\frac{1}{10} ÷ 0.01 =$
$\frac{5}{22} × 0.44 =$
$3.5 ÷ (2.8 × \frac{1}{4}) =$

1. 20 4.5 0.27 5
0.36 60 30 0.5
0.6 6 3.15 1.2
21 2 1.3 5.1
39 $\frac{1}{2}$ $\frac{11}{8}$ $\frac{1}{2}$
$\frac{3}{10}$ $\frac{10}{3}$ $\frac{1}{24}$ $2\frac{4}{19}$
$\frac{4}{15}$ $\frac{13}{20}$ 27 $\frac{4}{3}$
8.1 10 $\frac{1}{10}$ 5

2. 用竖式计算。
28.7÷1.4=
4.32×65=
18.15÷33=
0.28×7.75=
4.08×0.56≈
（得数保留一位小数）
7.83÷2.8≈
（得数保留两位小数）

2. 20.5 280.8 0.55
2.17 2.3 2.80
竖式略

在每个数适当的位置点上小数点，使式子成立。
1005＜927＜319＜421

1. $1.005＜9.27＜31.9＜42.1$