一、口算。
$10.8÷4=$
$0.63÷9=$
$0.16×6=$
$2.47×200=$
$2.04×9=$
$215+850=$
$12.24÷6=$
$259+441=$
$1560-78=$
$30×45=$
$5.4×8=$
$6.06÷3=$
$375÷3=$
$980-566=$
$2.25×4=$
$\frac{4}{5} - \frac{2}{3} =$
$\frac{2}{3} × \frac{5}{16} =$
$\frac{5}{6} + \frac{3}{4} =$
$\frac{4}{5} ÷ \frac{7}{10} =$
$\frac{1}{2} ÷ \frac{3}{10} =$
$\frac{18}{5} × \frac{2}{3} =$
$\frac{17}{24} × \frac{3}{4} =$
$15 ÷ \frac{5}{8} =$
$\frac{6}{13} ÷ \frac{9}{26} =$

1. $10.8÷4=2.7$
2. $0.63÷9=0.07$
3. $0.16×6=0.96$
4. $2.47×200=494$
5. $2.04×9=18.36$
6. $215+850=1065$
7. $12.24÷6=2.04$
8. $259+441=700$
9. $1560-78=1482$
10. $30×45=1350$
11. $5.4×8=43.2$
12. $6.06÷3=2.02$
13. $375÷3=125$
14. $980-566=414$
15. $2.25×4=9$
16. $\frac{4}{5} - \frac{2}{3} =\frac{2}{15}$
17. $\frac{2}{3} × \frac{5}{16} =\frac{5}{24}$
18. $\frac{5}{6} + \frac{3}{4} =\frac{19}{12}$
19. $\frac{4}{5} ÷ \frac{7}{10} =\frac{8}{7}$
20. $\frac{1}{2} ÷ \frac{3}{10} =\frac{5}{3}$
21. $\frac{18}{5} × \frac{2}{3} =\frac{12}{5}$
22. $\frac{17}{24} × \frac{3}{4} =\frac{17}{32}$
23. $15 ÷ \frac{5}{8} =24$
24. $\frac{6}{13} ÷ \frac{9}{26} =\frac{4}{3}$

二、计算下面各题。
$\frac{3}{7} ÷ \frac{5}{7} × \frac{3}{2}$
$\frac{5}{8} ÷ \frac{7}{40} × \frac{7}{20}$
$\frac{25}{9} ÷ \frac{5}{4} ÷ \frac{4}{5}$
$\frac{9}{8} × \frac{10}{3} × \frac{1}{9}$
$12 ÷ \frac{2}{5} × \frac{8}{25}$
$\frac{16}{5} × \frac{3}{8} × 15$

1. $\frac{3}{7} ÷ \frac{5}{7} × \frac{3}{2} =\frac{9}{10}$
2. $\frac{5}{8} ÷ \frac{7}{40} × \frac{7}{20} =\frac{5}{4}$
3. $\frac{25}{9} ÷ \frac{5}{4} ÷ \frac{4}{5} =\frac{25}{9}$
4. $\frac{9}{8} × \frac{10}{3} × \frac{1}{9} =\frac{5}{12}$
5. $12 ÷ \frac{2}{5} × \frac{8}{25} =\frac{48}{5}$
6. $\frac{16}{5} × \frac{3}{8} × 15 =18$