650×8的积的末尾只有一个0. .
2.5==50÷ = ÷50.
6: = %=0.25= ÷48= (填分数)
4÷5= = = = ÷80.
甲数和乙数的比是3:7,甲数就是乙数的. .
=0.75=15: = ÷40= %