一、口算。
$\frac{5}{6}-\frac{1}{5}=$ $\frac{1}{8}×\frac{1}{15}=$ $\frac{1}{8}÷\frac{24}{1}=$
$24×0.03=$ $\frac{4}{25}÷\frac{2}{5}=$ $6.55+3.55=$
$\frac{1}{3}+\frac{3}{4}=$ $4.2÷0.14=$ $\frac{7}{4}-\frac{1}{6}=$
$\frac{7}{12}+\frac{7}{16}=$ $0.8×15=$ $\frac{7}{15}×\frac{5}{21}=$
$10÷\frac{1}{15}=$ $5-4.25=$ $\frac{6}{7}+\frac{3}{14}=$
$430×20=$ $\frac{7}{8}-\frac{5}{24}=$ $3.2÷16\%=$
$1.25-1.1=$ $2.5×0.4=$ $2-\frac{2}{3}=$

一、$\dfrac{19}{30}$ $\dfrac{1}{120}$ 3
0.72 $\dfrac{2}{5}$ 10.1
$\dfrac{13}{12}$ 30 $\dfrac{19}{12}$
$\dfrac{49}{48}$ 12 $\dfrac{1}{9}$
150 0.75 $\dfrac{15}{14}$
8600 $\dfrac{2}{3}$ 20
0.15 1 $1\dfrac{1}{3}$

二、计算下面各题，怎样简便就怎样计算。
$3\frac{2}{9}-\frac{8}{11}+\frac{7}{9}-\frac{3}{11}$ $45×(\frac{1}{3}+\frac{5}{9}-40\%)$ $60\%÷[(\frac{1}{5}+\frac{1}{3})÷\frac{2}{9}]$
$3.7×4.51+5.49×3.7$ $[(\frac{1}{9}+\frac{5}{24})×6-\frac{1}{2}]÷\frac{5}{4}$

$1.原式=(3\frac {2}{9}+\frac {7}{9})-(\frac {8}{11}+\frac {3}{11})=3$
2.原式=15+25-18=22
$3.原式=\frac {3}{5}×\frac {15}{8}×\frac {2}{9}=\frac {1}{4}$
4.原式=3.7×(4.51+5.49)=37
$5.原式=\frac {17}{12}×\frac {4}{5}=\frac {17}{15}$