一、口算。
$10×800=$
$45÷0.15=$
$250×30=$
$350÷50=$
$4.5×40=$
$680÷17=$
$240÷0.12=$
$0.2×43=$
$240÷4=$
$44×60=$
$140÷7=$
$1.25÷25=$
$0.48÷0.06=$
$0.12×0.3=$
$32×80=$
$\frac{1}{3}÷\frac{1}{4}=$
$\frac{4}{5}×\frac{5}{6}=$
$\frac{1}{2}÷\frac{3}{5}=$
$\frac{4}{15}×\frac{5}{6}=$
$\frac{5}{8}÷\frac{3}{8}=$
$\frac{7}{10}×\frac{3}{14}=$
$\frac{2}{3}×\frac{7}{12}=$
$\frac{2}{15}÷\frac{8}{25}=$
$\frac{5}{8}÷\frac{1}{16}=$

1.$10×800=8000$
2.$45÷0.15=300$
3.$250×30=7500$
4.$350÷50=7$
5.$4.5×40=180$
6.$680÷17=40$
7.$240÷0.12=2000$
8.$0.2×43=8.6$
9.$240÷4=60$
10.$44×60=2640$
11.$140÷7=20$
12.$1.25÷25=0.05$
13.$0.48÷0.06=8$
14.$0.12×0.3=0.036$
15.$32×80=2560$
16.$\frac{1}{3}÷\frac{1}{4}=\frac{4}{3}$
17.$\frac{4}{5}×\frac{5}{6}=\frac{2}{3}$
18.$\frac{1}{2}÷\frac{3}{5}=\frac{5}{6}$
19.$\frac{4}{15}×\frac{5}{6}=\frac{2}{9}$
20.$\frac{5}{8}÷\frac{3}{8}=\frac{5}{3}$
21.$\frac{7}{10}×\frac{3}{14}=\frac{3}{20}$
22.$\frac{2}{3}×\frac{7}{12}=\frac{7}{18}$
23.$\frac{2}{15}÷\frac{8}{25}=\frac{5}{12}$
24.$\frac{5}{8}÷\frac{1}{16}=10$

二、算一算，比一比。
$\frac{4}{5} ÷ 3 =$
$\frac{4}{5} × 3 =$
$2.2 × 0.5 =$
$2.2 ÷ 0.5 =$
$\frac{1}{10} × \frac{1}{7} =$
$\frac{1}{70} ÷ \frac{1}{10} =$
$\frac{5}{9} × 2 =$
$\frac{10}{9} ÷ \frac{5}{9} =$
$15.5 ÷ 0.2 =$
$15.5 × 5 =$
$25.6 ÷ 4 =$
$25.6 × 0.25 =$
$1.76 ÷ 0.125 =$
$1.76 × 8 =$
$21.5 × 2 =$
$21.5 ÷ 0.5 =$
$8.4 × 0.4 =$
$8.4 ÷ 2.5 =$
$13.6 × 1.25 =$
$13.6 ÷ 0.8 =$

1.$\frac{4}{5} ÷ 3 =\frac{4}{15}$
2.$\frac{4}{5} × 3 =\frac{12}{5}$
3.$2.2 × 0.5 =1.1$
4.$2.2 ÷ 0.5 =4.4$
5.$\frac{1}{10} × \frac{1}{7} =\frac{1}{70}$
6.$\frac{1}{70} ÷ \frac{1}{10} =\frac{1}{7}$
7.$\frac{5}{9} × 2 =\frac{10}{9}$
8.$\frac{10}{9} ÷ \frac{5}{9} =2$
9.$15.5 ÷ 0.2 =77.5$
10.$15.5 × 5 =77.5$
11.$25.6 ÷ 4 =6.4$
12.$25.6 × 0.25 =6.4$
13.$1.76 ÷ 0.125 =14.08$
14.$1.76 × 8 =14.08$
15.$21.5 × 2 =43$
16.$21.5 ÷ 0.5 =43$
17.$8.4 × 0.4 =3.36$
18.$8.4 ÷ 2.5 =3.36$
19.$13.6 × 1.25 =17$
20.$13.6 ÷ 0.8 =17$