口算下面各题.2.3×0.3= 0.42×0.2= 1.4×0.7=0.16×0.6= 1.2×0.5= 2×0.45=
0.6= 成= : == %
3: =12÷ =0.75== %= (折数)
5: =0.25=3÷ == %.
18: ==七五折= %
÷ = :10=0.8== %