《2025年阳光假日暑假五年级数学人教版》

1. $\frac {1}{5}+\frac {2}{3}=\frac {2}{3}+\frac {(1)}{(5)}$

答案： $\frac{1}{5}$

2. $\frac {3}{7}+\frac {2}{9}+\frac {7}{9}=\frac {(\frac{3}{7})}{( )}+(\frac {2}{9}+\frac {7}{9})$

答案： $\frac{3}{7}$

3. $\frac {11}{13}-\frac {5}{12}-\frac {1}{12}=\frac {11}{13}-(\frac {5}{12}+\frac {1}{12})$

答案： $\frac{5}{12}$，$\frac{1}{12}$

4. $\frac {1}{4}+\frac {7}{15}+\frac {3}{4}+\frac {8}{15}=(\frac {\frac{1}{4}}{ }+\frac {\frac{3}{4}}{ })+(\frac {\frac{7}{15}}{ }+\frac {\frac{8}{15}}{ })$

答案： $\frac{1}{4}$，$\frac{3}{4}$，$\frac{7}{15}$，$\frac{8}{15}$

5. $(\frac {1}{12}+\frac {3}{4})+(\frac {7}{12}+\frac {1}{4})=(\frac {1}{12}+\frac {7}{12})+(\frac {3}{4}+\frac {1}{4})$

答案： $\frac{7}{12}$；$\frac{1}{4}$

二、判断对错。(对的画“√”，错的画“×”)
1. $\frac {3}{5}+\frac {5}{8}-\frac {1}{2}=\frac {3+5-1}{5+8-2}=\frac {7}{11}$ (×)
2. $1-\frac {3}{5}+\frac {2}{5}=1-1=0$ (×)
3. $\frac {5}{9}-\frac {5}{12}+\frac {1}{12}=\frac {1}{18}$ (×)

答案： 1. ×；2. ×；3. ×

1. 脱式计算。
$\frac {2}{3}+(\frac {1}{2}-\frac {1}{4})$ $\frac {4}{5}-\frac {3}{10}+\frac {2}{3}$ $\frac {1}{2}+\frac {1}{4}-\frac {1}{6}$
$\frac {1}{2}-(\frac {2}{3}-\frac {2}{5})$ $\frac {7}{8}-\frac {5}{12}+\frac {1}{6}$ $\frac {5}{6}-(\frac {1}{2}+\frac {1}{3})$

答案： 计算$\frac{2}{3}+(\frac{1}{2}-\frac{1}{4})$
解：
$\begin{aligned}&\frac{2}{3}+(\frac{1}{2}-\frac{1}{4})\\=&\frac{2}{3}+(\frac{2}{4}-\frac{1}{4})\\=&\frac{2}{3}+\frac{1}{4}\\=&\frac{8}{12}+\frac{3}{12}\\=&\frac{11}{12}\end{aligned}$
计算$\frac{4}{5}-\frac{3}{10}+\frac{2}{3}$
解：
$\begin{aligned}&\frac{4}{5}-\frac{3}{10}+\frac{2}{3}\\=&\frac{8}{10}-\frac{3}{10}+\frac{2}{3}\\=&\frac{1}{2}+\frac{2}{3}\\=&\frac{3}{6}+\frac{4}{6}\\=&\frac{7}{6}\end{aligned}$
计算$\frac{1}{2}+\frac{1}{4}-\frac{1}{6}$
解：
$\begin{aligned}&\frac{1}{2}+\frac{1}{4}-\frac{1}{6}\\=&\frac{6}{12}+\frac{3}{12}-\frac{2}{12}\\=&\frac{9}{12}-\frac{2}{12}\\=&\frac{7}{12}\end{aligned}$
计算$\frac{1}{2}-(\frac{2}{3}-\frac{2}{5})$
解：
$\begin{aligned}&\frac{1}{2}-(\frac{2}{3}-\frac{2}{5})\\=&\frac{1}{2}-(\frac{10}{15}-\frac{6}{15})\\=&\frac{1}{2}-\frac{4}{15}\\=&\frac{15}{30}-\frac{8}{30}\\=&\frac{7}{30}\end{aligned}$
计算$\frac{7}{8}-\frac{5}{12}+\frac{1}{6}$
解：
$\begin{aligned}&\frac{7}{8}-\frac{5}{12}+\frac{1}{6}\\=&\frac{21}{24}-\frac{10}{24}+\frac{4}{24}\\=&\frac{11}{24}+\frac{4}{24}\\=&\frac{5}{8}\end{aligned}$
计算$\frac{5}{6}-(\frac{1}{2}+\frac{1}{3})$
解：
$\begin{aligned}&\frac{5}{6}-(\frac{1}{2}+\frac{1}{3})\\=&\frac{5}{6}-(\frac{3}{6}+\frac{2}{6})\\=&\frac{5}{6}-\frac{5}{6}\\=&0\end{aligned}$
综上，答案依次为$\frac{11}{12}$；$\frac{7}{6}$；$\frac{7}{12}$；$\frac{7}{30}$；$\frac{5}{8}$；$0$。