一、直接写出得数。（共 32 分）
$3×1.25=$ $10.24-3.36=$ $10.52+2.19=$ $6.3÷0.01×0.1=$
$0.2×3.8=$ $2.01+0.9=$ $5.1÷17=$ $2.05×50×0.4=$
$2.26÷0.2=$ $9.72÷0.04=$ $7.2×0.4=$ $5-0.24×10=$
$11÷2=$ $14+2.87=$ $10-9.99=$ $4.4÷0.11×2=$
$2.7×2=$ $0.05×40=$ $0.12+0.8=$ $0÷4.9×8=$
$4-1.4=$ $5.24×80=$ $6.3÷21=$ $3.27+4.73-0.15=$
$\frac {5}{6}-\frac {2}{3}=$ $\frac {19}{20}×\frac {5}{19}=$ $\frac {7}{8}×\frac {8}{7}=$ $1-\frac {7}{13}+\frac {6}{13}=$
$\frac {3}{4}×\frac {7}{18}=$ $\frac {7}{15}+\frac {3}{10}=$ $\frac {25}{49}-\frac {3}{7}=$ $\frac {5}{6}-\frac {1}{6}+\frac {2}{3}=$

3.75 6.88 12.71 63
0.76 2.91 0.3 41
11.3 243 2.88 2.6
5.5 16.87 0.01 80
5.4 2 0.92 0
2.6 419.2 0.3 7.85
$\frac{1}{6}$ $\frac{1}{4}$ 1 $\frac{12}{13}$
$\frac{7}{24}$ $\frac{23}{30}$ $\frac{4}{49}$ $\frac{4}{3}$

二、计算下面各题，能简算的要简算。（共 18 分）
$\frac {3}{4}-\frac {5}{8}+\frac {9}{16}$ $\frac {1}{7}+\frac {3}{11}+\frac {6}{7}+\frac {8}{11}$ $\frac {3}{8}×\frac {1}{3}×\frac {16}{27}$
$\frac {3}{10}+\frac {3}{8}-\frac {2}{5}$ $\frac {13}{9}-(\frac {5}{7}+\frac {4}{9})-\frac {1}{7}$ $[2.8-(0.65+0.55)]÷40$

$\frac{11}{16}$ 2 $\frac{2}{27}$
$\frac{11}{40}$ $\frac{1}{7}$ 0.04

三、解方程。（共 18 分）
$2.4x÷6.4=1.2$ $0.9x+0.5x=10.5$ $4x-\frac {1}{3}=\frac {2}{3}$
$0.36+0.2x=0.64$ $(x-1.8)÷1.2=24$ $\frac {3}{14}+\frac {5}{6}-x=\frac {2}{3}$

$x=3.2$ $x=7.5$ $x=0.25$
$x=1.4$ $x=30.6$ $x=\frac{8}{21}$