小刚家种了5棵苹果树,今年一共收苹果215千克.有4棵苹果树平均每棵收苹果45千克,另一棵收苹果多少千克?
3:4= :8=9: == %
3÷ == :12=七成五= %
÷10==9: == :40.
18: = :20== ÷40=1.2.
1÷4= ÷12==6: = (小数)