一、口算。
$80\% × 45 =$ $\frac{7}{16} + \frac{3}{8} =$ $3 - 0.66 =$
$0.64 ÷ 0.5 =$ $\frac{9}{13} - \frac{9}{26} =$ $\frac{7}{13} ÷ \frac{7}{3} =$
$0.2 + 68\% =$ $\frac{5}{4} - \frac{5}{7} =$ $39 + 610 =$
$9.1 ÷ 1.3 =$ $\frac{6}{5} × \frac{6}{7} =$ $\frac{15}{17} - \frac{1}{3} =$
$\frac{2}{3} + \frac{5}{6} =$ $3.14 × 3^{2} =$ $1.57 ÷ 3.14 =$
$\frac{5}{13} ÷ \frac{7}{26} =$ $\frac{2}{3} + \frac{4}{7} =$ $5.4 - 0.54 =$
$3.75 × 4 =$ $6.3 - 6 =$ $85 ÷ 20 =$

一、36 $\dfrac{13}{16}$ 2.34
1.28 $\dfrac{9}{26}$ $\dfrac{3}{13}$
0.88 $\dfrac{15}{28}$ 649
7 $\dfrac{36}{35}$ $\dfrac{28}{51}$
$\dfrac{3}{2}$ 28.26 0.5
$\dfrac{10}{7}$ $\dfrac{26}{21}$ 4.86
15 0.3 $\dfrac{17}{4}$

二、计算下面各题，怎样简便就怎样计算。
$8.9 × 10.1$ $(\frac{1}{15} + \frac{1}{25}) × 15 × 25$ $\frac{3}{20} ÷ [50\% × (\frac{4}{5} + \frac{2}{5})]$
$85 - 84 × (\frac{1}{6} - \frac{1}{7})$ $1.25 × 46 + 2.5 × 27$ $(\frac{5}{6} × \frac{6}{11} - \frac{3}{11}) ÷ \frac{8}{33}$

二、89.89 40 $\dfrac{1}{4}$
83 125 $\dfrac{3}{4}$