一个圆柱的底面半径是2厘米,高是3厘米,侧面积是 厘米2,体积是 厘米3.
=8÷ = :20=0.25.
=15÷ = ÷30=七五折= %
6: == %= ÷32.
1.5=18÷ == :6= %
=3: = %= ÷20=0.75.