Question

8．

直接寫出得數(shù)． 31.2+8=	10-0.01=	4.2×0.05=
0.32÷0.8=	24×5=	2.8×$\frac{3}{7}$=
$\frac{3}{5}$+$\frac{3}{7}$=	$\frac{1}{9}$÷$\frac{9}{11}$=	2-$\frac{1}{5}$=
3×$\frac{2}{5}$÷$\frac{2}{5}$×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3×$\frac{2}{5}$÷$\frac{2}{5}$×3變形為（3×3）×（$\frac{2}{5}$÷$\frac{2}{5}$）計(jì)算．

解答 解：

31.2+8=39.2	10-0.01=9.99	4.2×0.05=0.21
0.32÷0.8=0.4	24×5=120	2.8×$\frac{3}{7}$=1.2
$\frac{3}{5}$+$\frac{3}{7}$=$\frac{36}{35}$	$\frac{1}{9}$÷$\frac{9}{11}$=$\frac{11}{81}$	2-$\frac{1}{5}$=1$\frac{4}{5}$
3×$\frac{2}{5}$÷$\frac{2}{5}$×3=9

點(diǎn)評 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．