一、口算。
$44 ÷ \frac{11}{10} =$
$\frac{3}{4} - \frac{5}{12} =$
$1 ÷ 7 + \frac{6}{7} =$
$105\% × 10\% =$
$\frac{5}{21} × \frac{9}{25} =$
$(6.8 - 2) ÷ 40\% =$
$\frac{5}{12} × \frac{3}{10} =$
$78\% ÷ \frac{13}{15} =$
$1.8 - 0.25 - 75\% =$
$\frac{3}{4} + \frac{2}{7} =$
$\frac{15}{91} × \frac{13}{20} =$
$\frac{2}{5} + \frac{3}{5} × 2 =$
$32 × 12.5\% =$
$75\% ÷ \frac{5}{7} =$
$25 ÷ ( \frac{1}{2} + \frac{1}{3} ) =$
$\frac{3}{10} ÷ \frac{4}{5} =$
$\frac{11}{12} - \frac{3}{8} =$
$48 × ( \frac{1}{2} - \frac{1}{8} ) =$
$\frac{16}{25} × \frac{5}{8} =$
$\frac{7}{9} + \frac{1}{6} =$
$4 ÷ \frac{38}{29} × \frac{38}{29} =$

1.$40$ 2.$\frac{1}{3}$ 3.$1$ 4.$0.105$ 5.$\frac{3}{35}$ 6.$12$ 7.$\frac{1}{8}$ 8.$\frac{9}{10}$ 9.$0.8$ 10.$\frac{29}{28}$ 11.$\frac{3}{28}$ 12.$\frac{8}{5}$ 13.$4$ 14.$\frac{21}{20}$ 15.$30$ 16.$\frac{3}{8}$ 17.$\frac{13}{24}$ 18.$18$ 19.$\frac{2}{5}$ 20.$\frac{17}{18}$ 21.$4$

二、计算下面各题，能用简便算法的就用简便算法。
$\frac{2}{19}×\frac{8}{25}+\frac{17}{25}÷\frac{19}{2}$
$\frac{1}{10}×\frac{2}{3}÷(80\%-\frac{1}{3})$
$(84\%÷3+8.72)÷\frac{9}{10}$
$\frac{7}{8}-\frac{1}{4}×(\frac{8}{9}÷\frac{2}{3})$
$\frac{1}{7}÷7+7÷\frac{1}{7}$
$\frac{5}{13}×\frac{9}{10}+\frac{5}{13}×10\%$

1.$\frac{2}{19}$ 2.$\frac{1}{7}$ 3.$10$ 4.$\frac{13}{24}$ 5.$49\frac{1}{49}$ 6.$\frac{5}{13}$