□28÷31,要使商是一位数,□里最大能填 ;要使商是二位数,□里最小是 .
0.6= 成= : == %
3: =12÷ =0.75== %= (折数)
5: =0.25=3÷ == %.
18: ==七五折= %
÷ = :10=0.8== %