+76﹣76=142, ﹣123﹣145=454, +242+319=780, ﹣328+112=261.
9:15==24÷ = %= (填小数)
4÷5= :40== %
4÷5=2÷ == 填小数.
6: ==0.6= ÷60= : = %
=15: =60%= ÷40= (填小数)