$\frac {1} {2},:\frac {1} {3}$=:
2 :3=
4 :2=:
$\frac {1} {2},:\frac {1} {3}$=
1 :2=
$1,:\frac {1} {3}$=:
1 :0.125=
0.2 :25%=
25% : 2.5%=:
1 :0.25=:
化简比0.2 :0.5=:
求比值(不是整数的用分数表示)2 :1=