一、口算。
$23\% + 19.8\% =$
$70 ÷ 35\% =$
$39\% ÷ \frac{13}{10} =$
$20 × 8\% =$
$80\% - \frac{5}{7} =$
$25\% × 0.2 =$
$12.3 + 120\% =$
$55\% × \frac{7}{22} =$
$1.3 - 27\% =$
$105\% ÷ 5\% =$
$\frac{9}{10} × 20\% =$
$3.2\% × 4 =$
$12 × 20\% =$
$90\% ÷ \frac{1}{9} =$
$\frac{2}{5} + 35\% =$
$4.6 ÷ 23\% =$
$66\% × \frac{5}{11} =$
$1 - 0.5\% =$
$7 ÷ 14\% =$
$\frac{3}{4} - 25\% =$
$0.18 × 10\% =$

$0.428$
$200$
$\frac{3}{10}$
$\frac{8}{5}$
$\frac{3}{35}$
$0.05$
$13.5$
$\frac{7}{40}$
$1.03$
$21$
$\frac{9}{50}$
$0.128$
$2.4$
$8.1$
$\frac{3}{4}$
$20$
$0.3$
$0.995$
$50$
$\frac{1}{2}$
$0.018$

二、计算下面各题，能用简便算法的就用简便算法。
58.4 + 58.4 × 2%
98.6 − 98.6 × 4%
112 × (1 − 20%)
1.25 × 32% × 250
1 ÷ (60% − 20%)
30% × $\frac{4}{9}$ − $\frac{1}{9}$ × 30%

$59.568$
$94.656$
$89.6$
$100$
$2.5$
$\frac{1}{10}$