一、口算。
$71\% +\frac {13}{50}=$
$33\% +28\% =$
$\frac {3}{4}-25\% =$
$38\% ×\frac {5}{19}=$
$10.3-23\% =$
$3.33÷0.9=$
$\frac {3}{4}-\frac {2}{7}=$
$0.17+30\% =$
$90\% ×\frac {4}{15}=$
$65\% ÷1.3\% =$
$\frac {6}{7}×140\% =$
$32\% ×\frac {1}{8}=$
$46\% -\frac {2}{5}=$
$200\% -98\% =$
$7.5÷5\% =$
$0.4×40\% =$
$42\% ×\frac {6}{7}=$
$7\% ÷35\% =$
$60×50\% =$
$10×10\% =$
$\frac {2}{3}×90\% =$

一、$\frac{97}{100}$ 0.61 $\frac{1}{2}$ 0.1 10.07 3.7 $\frac{13}{28}$ 0.47 $\frac{6}{25}$ 50 $\frac{6}{5}$ 0.04 0.06 1.02 150 0.16 0.36 0.2 30 1 $\frac{3}{5}$

二、计算下面各题。
$\frac {1}{5}×85\% +\frac {1}{10}×25\% $
$(80\% +25\% )×\frac {7}{3}+\frac {7}{10}$
$\frac {8}{3}-(4×50\% +40\% )$
$75\% ×[(\frac {7}{15}-\frac {1}{3})÷\frac {2}{3}]$
$(\frac {5}{12}+\frac {1}{6})÷(40\% ×87.5\% )$
$76×20\% +23×0.2+\frac {1}{5}$

二、$\frac{39}{200}$ $\frac{63}{20}$ $\frac{4}{15}$ $\frac{3}{20}$ $\frac{5}{3}$ 20

1. $\frac{1}{5}×85\% +\frac{1}{10}×25\%$
$=\frac{1}{5}×\frac{17}{20}+\frac{1}{10}×\frac{1}{4}$
$=\frac{17}{100}+\frac{1}{40}$
$=\frac{34}{200}+\frac{5}{200}$
$=\frac{39}{200}$
2. $(80\% +25\%)×\frac{7}{3}+\frac{7}{10}$
$=(0.8 + 0.25)×\frac{7}{3}+0.7$
$=1.05×\frac{7}{3}+0.7$
$=\frac{21}{20}×\frac{7}{3}+\frac{7}{10}$
$=\frac{49}{20}+\frac{14}{20}$
$=\frac{63}{20}$
3. $\frac{8}{3}-(4×50\% +40\%)$
$=\frac{8}{3}-(4×0.5 + 0.4)$
$=\frac{8}{3}-(2 + 0.4)$
$=\frac{8}{3}-2.4$
$=\frac{8}{3}-\frac{12}{5}$
$=\frac{40}{15}-\frac{36}{15}$
$=\frac{4}{15}$
4. $75\% ×[(\frac{7}{15}-\frac{1}{3})÷\frac{2}{3}]$
$=0.75×[(\frac{7}{15}-\frac{5}{15})÷\frac{2}{3}]$
$=0.75×[\frac{2}{15}×\frac{3}{2}]$
$=0.75×\frac{1}{5}$
$=\frac{3}{4}×\frac{1}{5}$
$=\frac{3}{20}$
5. $(\frac{5}{12}+\frac{1}{6})÷(40\% ×87.5\%)$
$=(\frac{5}{12}+\frac{2}{12})÷(0.4×0.875)$
$=\frac{7}{12}÷0.35$
$=\frac{7}{12}÷\frac{7}{20}$
$=\frac{7}{12}×\frac{20}{7}$
$=\frac{5}{3}$
6. $76×20\% +23×0.2+\frac{1}{5}$
$=76×0.2 + 23×0.2 + 0.2$
$=(76 + 23 + 1)×0.2$
$=100×0.2$
$=20$