如图为边长10分米的正方形,内侧有一个半径为20厘米的圆形,沿边长滚动一周,圆形滚动不到的地方有多大面积?
直接写出得数.3.8÷0.19= 0.73×1.25×0.8= 1.6×2.5= 0.15×15﹣5×0.15=1÷0.2= 1.8×3.6+6.4×1.8= 2.5×0.3= 1.25×3.2×0.25=
计算:12×2.5= 7.5×0.4= 1÷0.625= 8.4÷4.2=24÷4+56÷4= 2.5+2.5×3= 0.25×8= 12.5÷2.5=
口算1.6÷0.4= 0.77×1= 7.5÷3= 1.5×6=0.125×8= 31.4÷3.14= 1.4×10= 0.1×6.4=3.6×0.2= 1.5÷1.5= 2.8÷0.4= 2.3+1.8=10÷0.1= 4.16÷1= 0.45×0.1= 0.2×11=3.6÷2= 1.2÷0.02= 72÷0.9= 25×0.4=
直接写出得数.1÷0.125= 1.6×0.5= 0.25÷0.1= 4.8÷0.48×0.01=0.65×0.2= 10﹣0.99= 8.8﹣7.8= 5.4×2÷5.4×2=