(10- )×0=
4+ = 7- =
3.1+0.4= += 640÷16= ×3×4=
10÷= ×= 2.4×= 25×40%=
1.85﹣+= 1÷×= +0.375=
2.4﹣= (+)×2.4= 5÷×5÷=
10×45%= 1.25×8= 40×(1﹣20%)=