一、口算。
$1.95÷0.3=$
$0.08÷1.6=$
$0.25×8=$
$300×9=$
$1.24-0.76=$
$215-66=$
$101+49=$
$156÷4=$
$3.85÷0.5=$
$6.2×8=$
$4.62+1.89=$
$0.76×10=$
$\frac{3}{4}+\frac{3}{2}=$
$\frac{9}{14}÷\frac{9}{8}=$
$\frac{1}{5}÷3=$
$\frac{5}{8}÷\frac{3}{4}=$
$\frac{1}{20}+\frac{2}{5}=$
$\frac{4}{9}÷\frac{1}{3}=$
$\frac{3}{8}×2=$
$\frac{2}{3}×\frac{4}{5}=$
$0.6-\frac{3}{8}=$
$\frac{2}{9}÷\frac{4}{9}=$
$\frac{2}{3}÷9=$
$0.9×\frac{5}{21}=$

1. $1.95÷0.3=6.5$
2. $0.08÷1.6=0.05$
3. $0.25×8=2$
4. $300×9=2700$
5. $1.24-0.76=0.48$
6. $215-66=149$
7. $101+49=150$
8. $156÷4=39$
9. $3.85÷0.5=7.7$
10. $6.2×8=49.6$
11. $4.62+1.89=6.51$
12. $0.76×10=7.6$
13. $\frac{3}{4}+\frac{3}{2}=\frac{9}{4}$
14. $\frac{9}{14}÷\frac{9}{8}=\frac{4}{7}$
15. $\frac{1}{5}÷3=\frac{1}{15}$
16. $\frac{5}{8}÷\frac{3}{4}=\frac{5}{6}$
17. $\frac{1}{20}+\frac{2}{5}=\frac{9}{20}$
18. $\frac{4}{9}÷\frac{1}{3}=\frac{4}{3}$
19. $\frac{3}{8}×2=\frac{3}{4}$
20. $\frac{2}{3}×\frac{4}{5}=\frac{8}{15}$
21. $0.6-\frac{3}{8}=\frac{9}{40}$
22. $\frac{2}{9}÷\frac{4}{9}=\frac{1}{2}$
23. $\frac{2}{3}÷9=\frac{2}{27}$
24. $0.9×\frac{5}{21}=\frac{3}{14}$

二、根据比例的基本性质，在括号里填合适的数。
$9:8=13.5:( )$
$8:3.2=1.25:( )$
$2.7:( )=5:\frac{5}{4}$
$\frac{4}{3}:\frac{8}{25}=( ):\frac{4}{25}$
$\frac{1}{6}:\frac{1}{20}=\frac{16}{9}:( )$
$( ):4=\frac{4}{5}:8$
$0.24:0.4=( ):5$
$10:( )=\frac{2}{3}:\frac{4}{5}$
$( ):30=15:18$
$3:4=\frac{1}{20}:( )$
$0.7:\frac{2}{7}=( ):20$
$( ):84=\frac{5}{7}:10$
$( ):\frac{1}{2}=12:\frac{3}{5}$
$\frac{18}{5}:\frac{3}{5}=( ):\frac{1}{3}$
$( ):2.4=15:0.8$

1. $9:8=13.5:12$
2. $8:3.2=1.25:0.5$
3. $2.7:\frac{27}{40}=5:\frac{5}{4}$
4. $\frac{4}{3}:\frac{8}{25}=\frac{2}{3}:\frac{4}{25}$
5. $\frac{1}{6}:\frac{1}{20}=\frac{16}{9}:\frac{8}{15}$
6. $\frac{2}{5}:4=\frac{4}{5}:8$
7. $0.24:0.4=3:5$
8. $10:12=\frac{2}{3}:\frac{4}{5}$
9. $25:30=15:18$
10. $3:4=\frac{1}{20}:\frac{1}{15}$
11. $0.7:\frac{2}{7}=49:20$
12. $6:84=\frac{5}{7}:10$
13. $10:\frac{1}{2}=12:\frac{3}{5}$
14. $\frac{18}{5}:\frac{3}{5}=2:\frac{1}{3}$
15. $45:2.4=15:0.8$