一堆沙子有m吨,一辆汽车每次运走x吨,运5次后还剩下 吨.
2÷ =8: =0.75= %= .
20%= ÷40=40: = [填小数]=× .
÷12===10÷( )=.
= %=12÷ =9: =.
÷ == :16= 小数.