Question

4．直接寫出得數(shù)．

355+445=	1.28-0.72=	3.14÷0.1=	$\frac{5}{11}$×$\frac{2}{5}$=
52+32=	$\frac{3}{4}$×$\frac{5}{6}$×0=	$\frac{9}{14}$×$\frac{4}{5}$+$\frac{3}{5}$×$\frac{9}{14}$=	$\frac{3}{7}$+$\frac{5}{11}$+$\frac{4}{7}$+$\frac{6}{11}$=

Answer 1

分析 根據(jù)四則運(yùn)算的計(jì)算法則進(jìn)行計(jì)算即可求解．注意$\frac{9}{14}$×$\frac{4}{5}$+$\frac{3}{5}$×$\frac{9}{14}$根據(jù)乘法分配律計(jì)算，$\frac{3}{7}$+$\frac{5}{11}$+$\frac{4}{7}$+$\frac{6}{11}$根據(jù)加法交換律和結(jié)合律簡(jiǎn)算．

解答 解：

355+445=800	1.28-0.72=0.56	3.14÷0.1=31.4	$\frac{5}{11}$×$\frac{2}{5}$=$\frac{2}{11}$
52+32=34	$\frac{3}{4}$×$\frac{5}{6}$×0=0	$\frac{9}{14}$×$\frac{4}{5}$+$\frac{3}{5}$×$\frac{9}{14}$=$\frac{9}{10}$	$\frac{3}{7}$+$\frac{5}{11}$+$\frac{4}{7}$+$\frac{6}{11}$=2

點(diǎn)評(píng) 考查了四則運(yùn)算，關(guān)鍵是熟練掌握計(jì)算法則正確進(jìn)行計(jì)算．