一、口算。
4.8÷240% =
$\frac{1}{4}×\frac{2}{5} =$
16.5÷10% =
$\frac{1}{3}×60\% =$
110%×0.6 =
20%÷50% =
1.8÷36% =
25%×12 =
$\frac{5}{6}×12\% =$
$\frac{5}{9}×45\% =$
6% + $\frac{3}{5} =$
2.8 - 80% =
10×54% =
$\frac{3}{4} + \frac{5}{12} =$
$\frac{8}{9}×75\% =$
20%×$\frac{3}{4} =$
3.4% - 1.4% =
390%×0.02 =
$\frac{2}{5} + 205\% =$
12.5%×8 =
100%÷$\frac{4}{9} =$

$2$
$\frac{1}{10}$
$165$
$\frac{1}{5}$
$0.66$
$0.4$
$5$
$3$
$0.1$
$\frac{1}{4}$
$\frac{33}{50}$
$2$
$5.4$
$\frac{7}{6}$
$\frac{2}{3}$
$\frac{3}{20}$
$0.02$
$0.078$
$2.45$
$1$
$\frac{9}{4}$

二、计算下面各题，能用简便算法的就用简便算法。
$4000+4000×2.25\%$
$5500×(1+2.82\%)$
$3200×5.85\%×3+3200$
$42.6+58.4×20\%$
$8.8×150\%+1.2×1.5$
$(58\%+62\%)÷50\%$

$4090$
$5655.1$
$3761.6$
$54.28$
$15$
$2.4$