1. 填一填。 $1-\frac{1}{3}=(\quad)$ $1-\frac{4}{7}=(\quad)$

$1-\frac{1}{3}=(\frac{2}{3})$
$1-\frac{4}{7}=(\frac{3}{7})$

2. 照样子，算一算，填一填。
$1 - $ $( \dfrac{4}{9} )$ $( )$ $( )$ $( )$ $( )$ $( )$ $( )$ $( )$
$\dfrac{5}{9}$ $\dfrac{1}{7}$ $\dfrac{1}{2}$ $\dfrac{3}{11}$ $\dfrac{4}{5}$ $\dfrac{8}{12}$ $\dfrac{5}{6}$

$1-\dfrac{1}{7}=\dfrac{6}{7}$
$1-\dfrac{1}{2}=\dfrac{1}{2}$
$1-\dfrac{4}{10}=\dfrac{6}{10}$
$1-\dfrac{3}{11}=\dfrac{8}{11}$
$1-\dfrac{4}{5}=\dfrac{1}{5}$
$1-\dfrac{8}{12}=\dfrac{4}{12}$
$1-\dfrac{5}{6}=\dfrac{1}{6}$
括号里依次填入：$\dfrac{6}{7}$、$\dfrac{1}{2}$、$\dfrac{6}{10}$、$\dfrac{8}{11}$、$\dfrac{1}{5}$、$\dfrac{4}{12}$、$\dfrac{1}{6}$。

3. 算一算。
(1) $\frac{2}{9} + \begin{array}{|c|}\hline \frac{1}{9} \\\hline \frac{3}{9} \\\hline \frac{6}{9} \\\hline \end{array} = \begin{array}{|c|}\hline \\\hline \\\hline \\\hline \end{array}$
(2) $\frac{7}{8} - \begin{array}{|c|}\hline \frac{1}{8} \\\hline $$ \\\hline \frac{3}{8} \\\hline \end{array} = \begin{array}{|c|}\hline \\\hline \\\hline \\\hline \end{array}$
(3) $1 - \begin{array}{|c|}\hline \frac{3}{5} \\\hline \frac{2}{7} \\\hline \frac{3}{10} \\\hline \end{array} = \begin{array}{|c|}\hline \\\hline \\\hline \\\hline \end{array}$

(1)
$\frac{2}{9}+\frac{1}{9}=\frac{3}{9}$
$\frac{2}{9}+\frac{3}{9}=\frac{5}{9}$
$\frac{2}{9}+\frac{6}{9}=\frac{8}{9}$
(2)
$\frac{7}{8}-\frac{1}{8}=\frac{6}{8}$
$\frac{7}{8}-\frac{2}{8}=\frac{5}{8}$
$\frac{7}{8}-\frac{3}{8}=\frac{4}{8}$
(3)
$1-\frac{3}{5}=\frac{2}{5}$
$1-\frac{2}{7}=\frac{5}{7}$
$1-\frac{3}{10}=\frac{7}{10}$

4. 小红买了一张彩纸，做红花用了这张彩纸的$\frac{7}{10}$，剩下的她用来剪五角星。
（1）剪五角星用去了这张彩纸的几分之几？
（2）做红花比剪五角星多用去这张彩纸的几分之几？

$1 - \frac{7}{10} = \frac{3}{10}$
答：剪五角星用去了这张彩纸的$\frac{3}{10}$。
$\frac{7}{10} - \frac{3}{10} = \frac{4}{10}$
答：做红花比剪五角星多用去这张彩纸的$\frac{4}{10}$。