在下面的横线里填人适当的运算符号.28 0.5=14 28 2.5=11.227 4.5=6 28 0.5=56.
=0.75=21: = %.
10: = =0.5=5÷ = %.
5÷ =25%= :40= = 折.
÷25== = (小数)= %= 成.
12: == :4=0.25= 折.