直接写出得数。0.27×5= 2.8÷0.7= 12.5×8= 0.25×4= 9.9÷99=0.42×100= 6÷1000= 14.7÷7= 0.6×0.5= 2-0.23=
能简便计算的要简算 (1)(12.5﹣1.25)×8 (2)5.7×18.34﹣57×0.834 (3)38.7×0.412+5.88×3.87 (4)5.64+99×5.64 (5)20.1×35.22﹣3.522 (6)20.9﹣0.9×2.5.
口算 0.1×9.02= 1.6×3= 1.2×0.6= 100÷200= 6.2×0.3= 0.7+7.32= 0.6×07= 2.8÷70= 0.9×0.4= 2.1÷7÷0.1=
求下面各图形的面积
做一做,结果能约分的要约分,是假分数的要化成带分数.=========
计算下面图形面积.