-1.5,4, , , 5,-5
+ x=2 8∶x =∶ 50%x-9×3=25
0.22= 800×5%= ×30%= : =
5×3.14= 94.2÷3.14= 0.2×0.4= 2.5%×3=
642÷6= 0.9×99+0.9= 1.25×80= 2.5÷0.01=
÷ = 2﹣ ﹣ = 3﹣ ﹣ = ( ÷ )×30=