一、直接写得数。
$\frac{7}{8}+\frac{1}{2}=$ $\frac{1}{4}+\frac{1}{3}=$ $\frac{4}{5}-\frac{2}{3}=$
$1-\frac{4}{5}-\frac{1}{5}=$ $\frac{3}{7}+\frac{3}{7}=$ $\frac{2}{3}+\frac{4}{5}+\frac{1}{3}=$
$\frac{2}{9}+\frac{2}{9}=$ $\frac{1}{2}+\frac{1}{2}=$ $\frac{2}{15}+\frac{2}{15}=$

$\frac{7}{8}+\frac{1}{2}=\frac{11}{8}$
$\frac{1}{4}+\frac{1}{3}=\frac{7}{12}$
$\frac{4}{5}-\frac{2}{3}=\frac{2}{15}$
$1-\frac{4}{5}-\frac{1}{5}=0$
$\frac{3}{7}+\frac{3}{7}=\frac{6}{7}$
$\frac{2}{3}+\frac{4}{5}+\frac{1}{3}=\frac{9}{5}$
$\frac{2}{9}+\frac{2}{9}=\frac{4}{9}$
$\frac{1}{2}+\frac{1}{2}=1$
$\frac{2}{15}+\frac{2}{15}=\frac{4}{15}$

二、计算下面各题，并验算。
$\frac{5}{6}-\frac{5}{9}$
$\frac{3}{4}+\frac{1}{5}$
$\frac{6}{7}-\frac{1}{5}$

$\frac{5}{6}-\frac{5}{9}$
$=\frac{15}{18}-\frac{10}{18}$
$=\frac{5}{18}$
验算：
$\frac{5}{18}+\frac{5}{9}$
$=\frac{5}{18}+\frac{10}{18}$
$=\frac{15}{18}=\frac{5}{6}$
$\frac{3}{4}+\frac{1}{5}$
$=\frac{15}{20}+\frac{4}{20}$
$=\frac{19}{20}$
验算：
$\frac{19}{20}-\frac{1}{5}$
$=\frac{19}{20}-\frac{4}{20}$
$=\frac{15}{20}=\frac{3}{4}$
$\frac{6}{7}-\frac{1}{5}$
$=\frac{30}{35}-\frac{7}{35}$
$=\frac{23}{35}$
验算：
$\frac{23}{35}+\frac{1}{5}$
$=\frac{23}{35}+\frac{7}{35}$
$=\frac{30}{35}=\frac{6}{7}$

三、计算下列各题，能简算的要简算。
$\frac{4}{5}-\frac{3}{10}+\frac{1}{5}$
$\frac{24}{25}+\frac{4}{13}+\frac{5}{13}+\frac{4}{13}$
$3-(\frac{4}{11}-\frac{7}{11})$
$10-(\frac{2}{3}+\frac{1}{2})$
$\frac{4}{5}-\frac{1}{6}+\frac{1}{3}$
$1-(\frac{1}{2}+\frac{1}{7})$
暑假作业 数学 五年级
$\frac{3}{5}+\frac{1}{4}-\frac{2}{5}$
$1\frac{1}{2}-(\frac{4}{11}-\frac{7}{11})$
$\frac{5}{2}-(\frac{1}{4}+\frac{1}{3})$

$\frac{4}{5}-\frac{3}{10}+\frac{1}{5}$
$\begin{aligned}&=\frac{4}{5}+\frac{1}{5}-\frac{3}{10}\\&=1-\frac{3}{10}\\&=\frac{7}{10}\end{aligned}$
$\frac{24}{25}+\frac{4}{13}+\frac{5}{13}+\frac{4}{13}$
$\begin{aligned}&=\frac{24}{25}+(\frac{4}{13}+\frac{5}{13}+\frac{4}{13})\\&=\frac{24}{25}+1\\&=1\frac{24}{25}\end{aligned}$
$3-(\frac{4}{11}-\frac{7}{11})$
$\begin{aligned}&=3-(-\frac{3}{11})\\&=3+\frac{3}{11}\\&=3\frac{3}{11}\end{aligned}$
$10-(\frac{2}{3}+\frac{1}{2})$
$\begin{aligned}&=10-(\frac{4}{6}+\frac{3}{6})\\&=10-\frac{7}{6}\\&=\frac{53}{6}\\&=8\frac{5}{6}\end{aligned}$
$\frac{4}{5}-\frac{1}{6}+\frac{1}{3}$
$\begin{aligned}&=\frac{24}{30}-\frac{5}{30}+\frac{10}{30}\\&=\frac{29}{30}\end{aligned}$
$1-(\frac{1}{2}+\frac{1}{7})$
$\begin{aligned}&=1-(\frac{7}{14}+\frac{2}{14})\\&=1-\frac{9}{14}\\&=\frac{5}{14}\end{aligned}$
$\frac{3}{5}+\frac{1}{4}-\frac{2}{5}$
$\begin{aligned}&=\frac{3}{5}-\frac{2}{5}+\frac{1}{4}\\&=\frac{1}{5}+\frac{1}{4}\\&=\frac{9}{20}\end{aligned}$
$1\frac{1}{2}-(\frac{4}{11}-\frac{7}{11})$
$\begin{aligned}&=1\frac{1}{2}-(-\frac{3}{11})\\&=1\frac{1}{2}+\frac{3}{11}\\&=1\frac{17}{22}\end{aligned}$
$\frac{5}{2}-(\frac{1}{4}+\frac{1}{3})$
$\begin{aligned}&=\frac{5}{2}-(\frac{3}{12}+\frac{4}{12})\\&=\frac{30}{12}-\frac{7}{12}\\&=\frac{23}{12}\\&=1\frac{11}{12}\end{aligned}$