一、口算。
$936 + 764 =$
$4.5 × 0.8 =$
$125 ÷ 1000 =$
$0.88 ÷ 0.8 =$
$30.45 - 20.55 =$
$16.2 × 5 =$
$8.5 ÷ 17 =$
$6.93 - 5.13 =$
$1338 - 926 =$
$4.08 × 0.4 =$
$12.05 ÷ 5 =$
$7.32 + 5.28 =$
$\frac{5}{6} × \frac{7}{8} =$
$20 ÷ \frac{5}{6} =$
$\frac{5}{6} + \frac{4}{9} =$
$\frac{5}{13} × \frac{13}{15} =$
$\frac{7}{8} ÷ \frac{1}{16} =$
$\frac{4}{9} × 18 =$
$\frac{8}{9} × \frac{3}{4} =$
$1.25 × \frac{8}{5} =$
$\frac{9}{4} ÷ \frac{3}{4} =$
$\frac{4}{9} ÷ \frac{2}{3} =$
$\frac{2}{7} + \frac{5}{8} =$
$\frac{10}{21} × \frac{7}{15} =$

1. 1700
2. 3.6
3. 0.125
4. 1.1
5. 9.9
6. 81
7. 0.5
8. 1.8
9. 412
10. 1.632
11. 2.41
12. 12.6
13. $\frac{35}{48}$
14. 24
15. $\frac{23}{18}$
16. $\frac{1}{3}$
17. 14
18. 8
19. $\frac{2}{3}$
20. 2
21. 3
22. $\frac{2}{3}$
23. $\frac{51}{56}$
24. $\frac{2}{9}$

二、计算下面各题，能简算的要简算。
$24×\frac{51}{43}+51×\frac{19}{43}$
$\frac{3}{4}-\frac{3}{4}÷3+\frac{9}{25}$
$\frac{5}{6}-0.82-0.18+\frac{1}{6}$
$12.5×2.5×40×0.8$
$0.567×101-0.567$
$41.6÷(13.94+34.3×0.2)$

1. 51
2. $\frac{43}{50}$
3. 0
4. 1000
5. 56.7
6. 2