一、口算。
$880÷11=$
$0.04×500=$
$7.7÷77×10=$
$3.29+2.8=$
$5.2-2.72=$
$3.42×0.2-0.2=$
$0.13×40=$
$29.5-5.9=$
$120×0.25×0.4=$
$20.3+7.7=$
$24.8÷80=$
$(6.3+1.7)÷0.4=$
$\frac{6}{7}-\frac{2}{3}=$
$\frac{2}{3}÷\frac{5}{6}=$
$\frac{3}{4}×8×\frac{1}{2}=$
$\frac{14}{19}÷\frac{7}{19}=$
$\frac{1}{3}+0.75=$
$\frac{2}{5}÷\frac{6}{7}×\frac{3}{8}=$
$\frac{5}{8}+\frac{3}{4}=$
$6÷\frac{6}{7}=$
$1÷\frac{2}{5}×\frac{2}{5}=$
$0.6÷\frac{5}{8}=$
$\frac{4}{5}×\frac{3}{4}=$
$(\frac{7}{12}+\frac{3}{8})÷\frac{1}{48}=$

1. 80
2. 20
3. 1
4. 6.09
5. 2.48
6. 0.484
7. 5.2
8. 23.6
9. 12
10. 28
11. 0.31
12. 20
13. $\frac{4}{21}$
14. $\frac{4}{5}$
15. 3
16. 2
17. $\frac{13}{12}$
18. $\frac{7}{40}$
19. $\frac{11}{8}$
20. 7
21. 1
22. $\frac{24}{25}$
23. $\frac{3}{5}$
24. 46

二、计算下面各题，能简算的要简算。
$( \frac{3}{8} - \frac{3}{8} ÷ \frac{8}{3} ) × \frac{16}{9}$
$\frac{3}{5} × 9.8 + 0.6 × \frac{1}{5}$
$( \frac{5}{8} - \frac{1}{4} ) × ( \frac{8}{9} ÷ \frac{4}{15} )$
$18.6 × 6 + 1.4 × 6$
$3.61 ÷ (7.2 - 5.3) × 30$
$7.2 - 4.54 + 9.8 - 6.46$

1. $\frac{5}{12}$
2. 6
3. $\frac{5}{4}$
4. 120
5. 57
6. 6