Question

20．直接寫(xiě)出得數(shù)．

7.9-2.6=	4×25%=	10-0.97=	4×0.8×1.25=
$\frac{1}{5}-\frac{1}{6}$=	0÷$\frac{3}{4}$=	$\frac{8}{15}$×$\frac{1}{4}$=	$\frac{1}{7}+\frac{6}{7}$÷3=
3.2÷1.6=	$\frac{5}{4}$÷$\frac{4}{5}$=	$\frac{3}{5}$×$\frac{15}{16}$=	$\frac{1}{2}+\frac{1}{3}-\frac{1}{2}+\frac{1}{3}$=

Answer 1

分析 根據(jù)四則運(yùn)算的計(jì)算法則計(jì)算即可求解．注意4×0.8×1.25根據(jù)乘法結(jié)合律計(jì)算，$\frac{1}{2}+\frac{1}{3}-\frac{1}{2}+\frac{1}{3}$變形為（$\frac{1}{2}$-$\frac{1}{2}$）+（$\frac{1}{3}$+$\frac{1}{3}$）計(jì)算．

解答 解：

7.9-2.6=5.3	4×25%=1	10-0.97=9.03	4×0.8×1.25=4
$\frac{1}{5}-\frac{1}{6}$=$\frac{1}{30}$	0÷$\frac{3}{4}$=0	$\frac{8}{15}$×$\frac{1}{4}$=$\frac{2}{15}$	$\frac{1}{7}+\frac{6}{7}$÷3=$\frac{3}{7}$
3.2÷1.6=2	$\frac{5}{4}$÷$\frac{4}{5}$=$\frac{25}{16}$	$\frac{3}{5}$×$\frac{15}{16}$=$\frac{9}{16}$	$\frac{1}{2}+\frac{1}{3}-\frac{1}{2}+\frac{1}{3}$=$\frac{2}{3}$

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．