×4.2= 10.4﹣0.8= 44÷ = 0.11÷0.1=
÷ = 8.7÷29= × = 6×( ﹣ )=
19+23=
5﹣1.6=
0.23÷0.1=
0.4×0.2=
=
÷0.25=
大正方形的面积=边长2?用字母表示大正方形的面积S是: