一、口算。
$1.3 - 0.26=$ $9.6÷1.6=$ $0.8×0.25=$
$4×8.8=$ $1.3 + 8.66=$ $12.4 - 4.5=$
$5.5÷2.2=$ $1 - 0.01=$ $0.8×0.45=$
$0.62 - 0.35=$ $240×0.4=$ $8.1÷3=$
$37.5×200=$ $3.78 + 4.2=$ $20.5 - 2.05=$
$\frac{5}{7}-\frac{2}{11}=$ $\frac{7}{12}+\frac{2}{5}=$ $\frac{8}{15}-\frac{7}{25}=$
$\frac{7}{10}+\frac{3}{5}=$ $\frac{7}{3}-\frac{7}{10}=$ $\frac{4}{5}+\frac{16}{15}=$
$\frac{5}{6}-\frac{1}{4}=$ $\frac{4}{5}+\frac{3}{8}=$ $\frac{6}{7}-\frac{3}{14}=$
$\frac{5}{14}+\frac{3}{22}=$ $\frac{7}{9}-\frac{5}{18}=$ $\frac{1}{3}+\frac{5}{12}=$
$\frac{3}{4}-\frac{1}{16}=$ $\frac{1}{6}+\frac{2}{5}=$ $\frac{3}{7}+\frac{4}{9}=$

$1.04 6 0.235.2 9.96 7.92.5 0.99 0.360.27 96 2.77500 7.98 18.45\frac{41}{77} \frac{59}{60} \frac{19}{75}\frac{13}{10} \frac{49}{30} \frac{28}{15}\frac{7}{12} \frac{47}{40} \frac{9}{14}\frac{38}{77} \frac{1}{2} \frac{3}{4}\frac{11}{16} \frac{17}{30} \frac{55}{63}$

二、计算下面各题，怎样简便就怎样计算。
$\frac{6}{7}-\frac{1}{2}+\frac{19}{28}$ $\frac{23}{15}-(\frac{1}{3}+\frac{4}{5})$ $\frac{10}{21}-\frac{5}{14}+\frac{8}{21}-\frac{3}{14}$

$\frac{29}{28} \frac{2}{5} \frac{2}{7}$