用竖式计算.4.6+3.8= 13.9+9.1=8.4﹣1.7= 7﹣4.3=
10+20= 10+40= 10+50= 10+70= 20+20= 20+40= 20+50= 20+70=
30×1=____ 30×2=____ 30×3=____
20×1=____ 20×2=____ 20×3=____ 20×4=____
10×1=____ 10×2=____ 10×3=____ 10×4=____
41+7= 43+4= 47+7= 48+8= 81+7= 83+4= 87+7= 88+8=