圆柱的底面半径扩大3倍,高缩小到原来的,它的体积不变. .(判断对错)
%=7÷8= (填小数).
13.5÷ ==0.45=18: = %
÷24=0.375=15: = :16= %
3÷5== %=9: = 折.
4:5= (填小数)=0.8: .