Question

15．直接寫(xiě)出得數(shù)

$\frac{18}{25}$+$\frac{5}{9}$	$\frac{18}{25}$×$\frac{5}{9}$	$\frac{5}{27}$+1	$\frac{5}{27}$×120
$\frac{16}{39}$×$\frac{13}{32}$	$\frac{15}{34}$×$\frac{17}{30}$	$\frac{5}{8}$-$\frac{5}{12}$	$\frac{12}{25}$÷6

Answer 1

分析 根據(jù)分?jǐn)?shù)加減乘除的計(jì)算方法進(jìn)行計(jì)算即可．

解答 解：

$\frac{18}{25}$+$\frac{5}{9}$=$\frac{287}{225}$	$\frac{18}{25}$×$\frac{5}{9}$=$\frac{2}{5}$	$\frac{5}{27}$+1=$\frac{32}{27}$	$\frac{5}{27}$×120=$\frac{200}{9}$
$\frac{16}{39}$×$\frac{13}{32}$=$\frac{1}{6}$	$\frac{15}{34}$×$\frac{17}{30}$=$\frac{1}{4}$	$\frac{5}{8}$-$\frac{5}{12}$=$\frac{5}{24}$	$\frac{12}{25}$÷6=$\frac{2}{25}$

點(diǎn)評(píng) 口算時(shí)注意數(shù)據(jù)的通分，然后再進(jìn)一步計(jì)算．