一、口算。
2.4 - 0.15 =
560 ÷ 20 =
0.91 ÷ 13 =
106 × 5 =
129 + 345 =
4.25 + 0.75 =
540 - 170 =
12.5 × 6 =
9.5 ÷ 0.5 =
1.54 ÷ 0.2 =
1.01 - 0.11 =
36 × 30 =
8.8 + 0.12 =
800 × 20 =
690 ÷ 230 =
$\frac{4}{9}×\frac{1}{6}=$
$\frac{4}{5}+\frac{1}{4}=$
$\frac{7}{3}÷\frac{7}{10}=$
$\frac{5}{7}÷\frac{5}{14}=$
$\frac{3}{4}-\frac{7}{10}=$
$\frac{4}{7}×\frac{7}{4}=$
$\frac{7}{8}÷\frac{2}{3}=$
$\frac{2}{9}+\frac{7}{12}=$
$\frac{5}{7}+\frac{1}{2}=$

1. 2.25
2. 28
3. 0.07
4. 530
5. 474
6. 5
7. 370
8. 75
9. 19
10. 7.7
11. 0.9
12. 1080
13. 8.92
14. 16000
15. 3
16. $\frac{2}{27}$
17. $\frac{21}{20}$
18. $\frac{10}{3}$
19. 2
20. $\frac{1}{20}$
21. 1
22. $\frac{21}{16}$
23. $\frac{29}{36}$
24. $\frac{17}{14}$

二、计算下面各题，能简算的要简算。
$(1-\dfrac{8}{15}×\dfrac{1}{2})÷\dfrac{4}{5}$
$(\dfrac{1}{8}+\dfrac{3}{4})×(1-\dfrac{1}{3})$
$\dfrac{1}{8}×125+\dfrac{1}{8}×42+\dfrac{1}{8}$
$5.5×17.3+6.7×5.5$
$7.74×[2.8-(1.3+1.5)]$
$7.5+(32.4-11.6)÷0.64$

1. $\frac{11}{12}$
2. $\frac{7}{12}$
3. 21
4. 132
5. 0
6. 40