桌面的大小就是桌面的面积. .
= ÷0.8=0.875= :24.
÷16== : = (填小数)
3÷ =6÷8= ÷12=51÷ = 填小数.
÷8=21÷ == : = (小数).
÷ ==3: = :24= (填小数)