1. 求比值。
$8:2=$
$7:6=$
$0.45:1.5=$
$7:3.5=$
$2.4:0.32=$
$3.2:9.6=$
$14:35=$
$1.7:0.4=$
$3.75:2.5=$
$1.5:2.1=$
$3.3:1.6=$
$0.125:5=$
$3:0.6=$
$4.5:3.5=$
$0.12:0.36=$
$8.1:0.27=$
$0.64:0.8=$
$0.8:0.75=$
$8:4.5=$
$0.375:0.625=$
$0.2:0.7=$
$0.8:0.6=$
$2.5:0.45=$
$0.75:0.25=$
$24:\frac{8}{27}=$
$\frac{1}{8}:\frac{1}{4}=$
$\frac{4}{5}:\frac{16}{15}=$
$\frac{3}{5}:\frac{3}{7}=$
$\frac{5}{8}:15=$
$\frac{1}{6}:\frac{2}{3}=$
$\frac{3}{2}:\frac{3}{5}=$
$0.5:\frac{1}{6}=$

1. $8:2=4$
$7:6=\frac{7}{6}$
$0.45:1.5=0.3$
$7:3.5=2$
$2.4:0.32=7.5$
$3.2:9.6=\frac{1}{3}$
$14:35=\frac{2}{5}$
$1.7:0.4=\frac{17}{4}$
$3.75:2.5=1.5$
$1.5:2.1=\frac{5}{7}$
$3.3:1.6=\frac{33}{16}$
$0.125:5=\frac{1}{40}$
$3:0.6=5$
$4.5:3.5=\frac{9}{7}$
$0.12:0.36=\frac{1}{3}$
$8.1:0.27=30$
$0.64:0.8=0.8$
$0.8:0.75=\frac{16}{15}$
$8:4.5=\frac{16}{9}$
$0.375:0.625=0.6$
$0.2:0.7=\frac{2}{7}$
$0.8:0.6=\frac{4}{3}$
$2.5:0.45=\frac{50}{9}$
$0.75:0.25=3$
$24:\frac{8}{27}=81$
$\frac{1}{8}:\frac{1}{4}=\frac{1}{2}$
$\frac{4}{5}:\frac{16}{15}=\frac{3}{4}$
$\frac{3}{5}:\frac{3}{7}=\frac{7}{5}$
$\frac{5}{8}:15=\frac{1}{24}$
$\frac{1}{6}:\frac{2}{3}=\frac{1}{4}$
$\frac{3}{2}:\frac{3}{5}=\frac{5}{2}$
$0.5:\frac{1}{6}=3$

2. 用竖式计算，带☆的要验算。
6.06×1.4=
☆5.22÷29=
☆4.8×7.14=
0.76×5.6=
☆0.512÷0.32=
400÷75=
（商用循环小数表示）

2. 6.06×1.4=8.484
☆5.22÷29=0.18
☆4.8×7.14=34.272
0.76×5.6=4.256
☆0.512÷0.32=1.6
400÷75=$5.\dot{3}$
竖式及验算略

已知A，B是1～100中的两个不同自然数，则$(A + B):(A - B)$的比值最大是多少？

$(A+B):(A-B)=(100+99):(100-99)=199$