80×30%=
× =
× ÷ × =
3.14×4²=
4000×87.5%=
84÷(1﹣30%)=
x×( +0.25)=36
: = :x
1.25×32×0.25
× +15×0.375+0.4×37.5%
÷ ×(1﹣ )