1. 求比值。(20☆)
$\frac{3}{10}:3=$
$2.1:0.7=$
$12.1:11=$
$8.1:9=$
$0.48:3=$
$0.75:0.5=$
$\frac{2}{3}:8=$
$0.81:0.3=$
$2:0.125=$
$0.56:4=$
$20.5:\frac{5}{7}=$
$\frac{1}{42}:\frac{1}{21}=$
$0.6:\frac{3}{10}=$
$\frac{8}{7}:\frac{2}{5}=$
$42:\frac{7}{8}=$
$0.4:1.5=$
$\frac{4}{5}:1.8=$
$21:\frac{3}{14}=$
$\frac{4}{15}:90=$
$\frac{5}{8}:\frac{3}{4}=$

1.$\frac{3}{10}:3=0.1$
2.$2.1:0.7=3$
3.$12.1:11=1.1$
4.$8.1:9=0.9$
5.$0.48:3=0.16$
6.$0.75:0.5=1.5$
7.$\frac{2}{3}:8=\frac{1}{12}$
8.$0.81:0.3=2.7$
9.$2:0.125=16$
10.$0.56:4=0.14$
11.$20.5:\frac{5}{7}=28.7$
12.$\frac{1}{42}:\frac{1}{21}=0.5$
13.$0.6:\frac{3}{10}=2$
14.$\frac{8}{7}:\frac{2}{5}=\frac{20}{7}$
15.$42:\frac{7}{8}=48$
16.$0.4:1.5=\frac{4}{15}$
17.$\frac{4}{5}:1.8=\frac{4}{9}$
18.$21:\frac{3}{14}=98$
19.$\frac{4}{15}:90=\frac{2}{675}$
20.$\frac{5}{8}:\frac{3}{4}=\frac{5}{6}$

2. 在括号里填上合适的数。(18☆)
$2:3=(\ \ ):6$
$1.2:5.2=6:(\ \ )$
$\frac{2}{9}:\frac{5}{3}=(\ \ ):5$
$10:8=(\ \ ):4$
$2.1:1.8=0.7:(\ \ )$
$\frac{7}{5}:\frac{3}{4}=(\ \ ):15$
$5:7=(\ \ ):14$
$0.25:0.16=0.5:(\ \ )$
$\frac{3}{4}:\frac{9}{5}=(\ \ ):36$

1.$2:3=4:6$
2.$1.2:5.2=6:26$
3.$\frac{2}{9}:\frac{5}{3}=\frac{2}{3}:5$
4.$10:8=5:4$
5.$2.1:1.8=0.7:0.6$
6.$\frac{7}{5}:\frac{3}{4}=28:15$
7.$5:7=10:14$
8.$0.25:0.16=0.5:0.32$
9.$\frac{3}{4}:\frac{9}{5}=15:36$

3. 计算下面各题,能简算的要简算。(12☆)
$\frac{5}{14}÷\frac{4}{21}×\frac{7}{25}$
$\frac{1}{12}÷(\frac{1}{4}+\frac{2}{3})$
$\frac{7}{8}×0.375+\frac{3}{8}÷\frac{8}{9}$
$(\frac{7}{9}+\frac{5}{27})×54$
$\frac{18}{35}÷0.6×\frac{3}{2}$
$\frac{2}{9}+\frac{1}{8}÷\frac{4}{5}+\frac{59}{32}$

1.$\frac{5}{14}÷\frac{4}{21}×\frac{7}{25}=\frac{21}{40}$
2.$\frac{1}{12}÷(\frac{1}{4}+\frac{2}{3})=\frac{1}{11}$
3.$\frac{7}{8}×0.375+\frac{3}{8}÷\frac{8}{9}=\frac{3}{4}$
4.$(\frac{7}{9}+\frac{5}{27})×54=52$
5.$\frac{18}{35}÷0.6×\frac{3}{2}=\frac{9}{7}$
6.$\frac{2}{9}+\frac{1}{8}÷\frac{4}{5}+\frac{59}{32}=\frac{20}{9}$