一、直接写出得数。（共32分）
$4.7 + 3.5 =$
$0.8 × 100 =$
$0.72 ÷ \frac{4}{5} =$
$6.4 × 9 + 6.4 =$
$10 - 0.9 =$
$3.2 ÷ 0.4 =$
$10 - 1.55 =$
$75 × 4.4 × 0 =$
$0.16 ÷ 8 =$
$0.21 × 2 =$
$6.24 + 0.82 =$
$7.2 - 7.2 ÷ 9 =$
$0.3 × 0.4 =$
$16 ÷ 0.25 =$
$2.2 × 0.5 =$
$0.5 × 1.4 × 1 =$
$\frac{24}{7} × \frac{35}{6} =$
$\frac{5}{6} + 1.5 =$
$\frac{8}{9} ÷ \frac{64}{81} =$
$\frac{6}{5} × 0.1 ÷ \frac{4}{5} =$
$\frac{3}{4} × \frac{4}{25} =$
$7.5 × \frac{16}{15} =$
$\frac{6}{5} ÷ \frac{18}{25} =$
$\frac{1}{7} × \frac{14}{3} - \frac{1}{9} =$
$72 × \frac{11}{8} =$
$\frac{11}{18} - \frac{1}{12} =$
$\frac{6}{11} × \frac{11}{72} =$
$(1 - 0.3) × \frac{10}{9} =$
$\frac{17}{7} × \frac{14}{51} =$
$\frac{7}{6} × \frac{1}{21} =$
$\frac{13}{18} ÷ \frac{26}{27} =$
$\frac{3}{4} × \frac{7}{8} + \frac{7}{8} =$

$8.2$
$80$
$0.9$
$64$
$9.1$
$8$
$8.45$
$0$
$0.02$
$0.42$
$7.06$
$6.4$
$0.12$
$64$
$1.1$
$0.7$
$20$
$\frac{7}{3}$
$\frac{9}{8}$
$0.15$
$\frac{3}{25}$
$8$
$\frac{5}{3}$
$\frac{5}{9}$
$99$
$\frac{19}{36}$
$\frac{1}{12}$
$\frac{7}{9}$
$\frac{2}{3}$
$\frac{1}{18}$
$\frac{3}{4}$
$\frac{49}{32}$

二、用竖式计算，带☆的要验算。（共20分）
7.6×3.08=
☆8.4÷0.56=
0.67÷0.34≈
（得数保留两位小数）
0.726÷2.4=
3.53×0.27≈
（得数保留一位小数）
☆6.04×0.93=

$23.408$
$15$
$1.97$
$0.3025$
$1.0$
$5.6172$
竖式及验算略

三、计算下面各题，怎样算简便就怎样算。（共24分）
$3.87 + 12.5×4.2 - 0.8$
$(\frac{5}{2} + 12.5)×4×8$
$7.2÷\frac{1}{4} + 2.8×4$
$8÷\frac{8}{9} - \frac{8}{9}÷8$
$12÷[(\frac{7}{9} - \frac{2}{3})×0.9]$
$\frac{1}{3}÷(\frac{7}{4} - \frac{2}{3})×\frac{13}{8}$

$55.57$
$480$
$40$
$8\frac{8}{9}$
$120$
$\frac{1}{2}$