Question

12．直接寫出得數(shù)．

4.2÷0.07=	5.2×6.8≈	1-34%=	36-26÷2=	7.2÷2.5÷4=
$\frac{9}{10}$÷$\frac{1}{3}$=	$\frac{5}{6}$-$\frac{3}{8}$=	6.6+0.44=	$\frac{2}{5}$×$\frac{1}{2}$÷$\frac{2}{5}$×$\frac{1}{2}$=	10-3.045=

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7.2÷2.5÷4根據(jù)除法的性質(zhì)計(jì)算，$\frac{2}{5}$×$\frac{1}{2}$÷$\frac{2}{5}$×$\frac{1}{2}$變形為（$\frac{2}{5}$÷$\frac{2}{5}$）×（$\frac{1}{2}$×$\frac{1}{2}$）計(jì)算．

解答 解：

4.2÷0.07=60	5.2×6.8≈35	1-34%=0.66	36-26÷2=23	7.2÷2.5÷4=0.72
$\frac{9}{10}$÷$\frac{1}{3}$=$\frac{27}{10}$	$\frac{5}{6}$-$\frac{3}{8}$=$\frac{11}{24}$	6.6+0.44=7.04	$\frac{2}{5}$×$\frac{1}{2}$÷$\frac{2}{5}$×$\frac{1}{2}$=$\frac{1}{4}$	10-3.045=6.955

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