Question

9．直接寫(xiě)得數(shù)．

0.25×8=	30.5÷100=	$\frac{5}{16}$×8=	$\frac{1}{4}$+$\frac{1}{2}$+$\frac{7}{4}$=
$\frac{1}{4}$÷$\frac{1}{5}$=	$\frac{4}{13}$×$\frac{1}{8}$=	$\frac{2}{9}$×0.3=	0÷$\frac{1}{15}$×$\frac{1}{5}$=

Answer 1

分析 根據(jù)小數(shù)和分?jǐn)?shù)加減乘除法的計(jì)算方法進(jìn)行計(jì)算；
$\frac{1}{4}$+$\frac{1}{2}$+$\frac{7}{4}$根據(jù)加法交換律進(jìn)行簡(jiǎn)算．

解答 解：

0.25×8=2	30.5÷100=0.305	$\frac{5}{16}$×8=$\frac{5}{2}$	$\frac{1}{4}$+$\frac{1}{2}$+$\frac{7}{4}$=2$\frac{1}{2}$
$\frac{1}{4}$÷$\frac{1}{5}$=$\frac{5}{4}$	$\frac{4}{13}$×$\frac{1}{8}$=$\frac{1}{26}$	$\frac{2}{9}$×0.3=$\frac{1}{15}$	0÷$\frac{1}{15}$×$\frac{1}{5}$=0

點(diǎn)評(píng) 口算時(shí)，注意運(yùn)算符號(hào)和數(shù)據(jù)，然后再進(jìn)一步計(jì)算．