1. 看图列式计算。
(1)
$
1 - \frac{4}{7} = $(
(2)
$
$(
(1)
$
$\frac {7}{7}$
) - ($\frac {4}{7}$
) = ($\frac {3}{7}$
)(2)
$
1
) - ($\frac {3}{8}$
) = ($\frac {8}{8}$
) - ($\frac {3}{8}$
) = ($\frac {5}{8}$
)答案
1.
(1)$\frac {7}{7}$ $\frac {4}{7}$ $\frac {3}{7}$
(2)1 $\frac {3}{8}$ $\frac {8}{8}$ $\frac {3}{8}$ $\frac {5}{8}$
(1)$\frac {7}{7}$ $\frac {4}{7}$ $\frac {3}{7}$
(2)1 $\frac {3}{8}$ $\frac {8}{8}$ $\frac {3}{8}$ $\frac {5}{8}$
2. 算一算。
$\frac{6}{9} - \frac{4}{9} = $
$1 - \frac{1}{4} = $
$\frac{6}{9} - \frac{4}{9} = $
$\frac {2}{9}$
$\frac{4}{6} + \frac{2}{6} = $1
$\frac{3}{7} - \frac{1}{7} = $$\frac {2}{7}$
$1 - \frac{3}{10} = $$\frac {7}{10}$
$1 - \frac{1}{4} = $
$\frac {3}{4}$
$\frac{1}{5} + \frac{4}{5} = $1
$1 - \frac{1}{3} = $$\frac {2}{3}$
$1 - \frac{6}{9} = $$\frac {3}{9}$
答案
2.$\frac {2}{9}$ 1 $\frac {2}{7}$ $\frac {7}{10}$ $\frac {3}{4}$ 1 $\frac {2}{3}$ $\frac {3}{9}$
3. 在○里填上“>”“<”或“=”。
$\frac{3}{6} + \frac{2}{6}$ ◯
$\frac{7}{8} - \frac{3}{8}$ ◯
$1 - \frac{7}{9}$ ◯
$\frac{6}{7} - \frac{2}{7}$ ◯
$\frac{2}{10} + \frac{6}{10}$ ◯
$\frac{2}{5} + \frac{1}{5}$ ◯
$\frac{3}{6} + \frac{2}{6}$ ◯
>
$1 - \frac{3}{6}$$\frac{7}{8} - \frac{3}{8}$ ◯
<
$\frac{3}{8} + \frac{2}{8}$$1 - \frac{7}{9}$ ◯
<
$1 - \frac{4}{9}$$\frac{6}{7} - \frac{2}{7}$ ◯
=
$1 - \frac{3}{7}$$\frac{2}{10} + \frac{6}{10}$ ◯
>
$1 - \frac{3}{10}$$\frac{2}{5} + \frac{1}{5}$ ◯
<
$1 - \frac{1}{5}$答案
3.> < < = > <
解析
$\frac{3}{6} + \frac{2}{6} = \frac{5}{6}$,$1 - \frac{3}{6} = \frac{3}{6}$,$\frac{5}{6}>\frac{3}{6}$,所以填“>”;
$\frac{7}{8} - \frac{3}{8} = \frac{4}{8}$,$\frac{3}{8} + \frac{2}{8} = \frac{5}{8}$,$\frac{4}{8}<\frac{5}{8}$,所以填“<”;
$1 - \frac{7}{9} = \frac{2}{9}$,$1 - \frac{4}{9} = \frac{5}{9}$,$\frac{2}{9}<\frac{5}{9}$,所以填“<”;
$\frac{6}{7} - \frac{2}{7} = \frac{4}{7}$,$1 - \frac{3}{7} = \frac{4}{7}$,$\frac{4}{7}=\frac{4}{7}$,所以填“=”;
$\frac{2}{10} + \frac{6}{10} = \frac{8}{10}$,$1 - \frac{3}{10} = \frac{7}{10}$,$\frac{8}{10}>\frac{7}{10}$,所以填“>”;
$\frac{2}{5} + \frac{1}{5} = \frac{3}{5}$,$1 - \frac{1}{5} = \frac{4}{5}$,$\frac{3}{5}<\frac{4}{5}$,所以填“<”。
> < < = > <
$\frac{7}{8} - \frac{3}{8} = \frac{4}{8}$,$\frac{3}{8} + \frac{2}{8} = \frac{5}{8}$,$\frac{4}{8}<\frac{5}{8}$,所以填“<”;
$1 - \frac{7}{9} = \frac{2}{9}$,$1 - \frac{4}{9} = \frac{5}{9}$,$\frac{2}{9}<\frac{5}{9}$,所以填“<”;
$\frac{6}{7} - \frac{2}{7} = \frac{4}{7}$,$1 - \frac{3}{7} = \frac{4}{7}$,$\frac{4}{7}=\frac{4}{7}$,所以填“=”;
$\frac{2}{10} + \frac{6}{10} = \frac{8}{10}$,$1 - \frac{3}{10} = \frac{7}{10}$,$\frac{8}{10}>\frac{7}{10}$,所以填“>”;
$\frac{2}{5} + \frac{1}{5} = \frac{3}{5}$,$1 - \frac{1}{5} = \frac{4}{5}$,$\frac{3}{5}<\frac{4}{5}$,所以填“<”。
> < < = > <
4. 明明看一本书,看了一星期后还剩下这本书的$\frac{3}{4}$。明明看了这本书的几分之几?
答案
4.$1-\frac {3}{4}=\frac {1}{4}$
把一张长方形彩纸对折 3 次后沿折痕剪开,做窗花用去其中的 3 份,做折纸用去其中的 2 份。这张彩纸还剩几分之几?
答案
$2×2×2=8$(份) $\frac {3}{8}+\frac {2}{8}=\frac {5}{8}$ $1-\frac {5}{8}=\frac {3}{8}$
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