一、口算。（每题1分，共30分）
$9.2\div2.3=$ $0.63 + 0.37=$ $2.75 + 2.75\times9=$
$0.125\times64=$ $8.2 - 2.55=$ $6\div(0.5\times4)=$
$96\div320=$ $3.2\times0.4=$ $20 - 3.7 - 7.3=$
$1.8\times6=$ $8.4\div4.2=$ $12.1-(2.1 + 7.4)=$
$2.63 + 0.37=$ $20 - 0.94=$ $6.9 - 3.09 + 3.1=$
$48\div0.3=$ $16\times2.5=$ $1.25\times2.3\times0.8=$
$\frac{2}{3}+\frac{3}{2}=$ $\frac{3}{4}+\frac{1}{6}=$ $\frac{2}{3}+\frac{4}{5}+\frac{1}{3}=$
$2-\frac{2}{3}=$ $\frac{3}{5}+\frac{4}{7}=$ $1-\frac{4}{9}+\frac{5}{9}=$
$\frac{4}{5}-\frac{4}{7}=$ $\frac{5}{13}+\frac{23}{65}=$ $\frac{6}{7}+\frac{8}{13}+\frac{1}{7}=$
$\frac{2}{3}-\frac{5}{9}=$ $\frac{7}{5}-\frac{1}{4}=$ $\frac{19}{18}-\frac{4}{5}-\frac{1}{5}=$

二、解方程。（每题3分，共27分）
$4.6\times2 + x = 12.8$ $3.4x + 0.3x = 14.8$ $6x - 4.2\times3 = 1.98$
$0.04x\div1.6 = 2.8$ $8x + 2.4 - 4.6 = 5.2$ $2x - 3.5 + 4.5 = 12$
$2x-\frac{4}{7}=\frac{3}{7}$ $\frac{3}{10}+\frac{5}{8}-x=\frac{1}{4}$ $x-\frac{2}{3}+\frac{1}{8}=\frac{1}{6}$