四年级数学题；用简便的方法计算:（递等式）120+653+47,440+123+60,412+35+75,119+345+181+55,66+34+533+

分类: 作业答案 • 2021-12-20 01:40:48

问题描述：

答

120+653+47
=120+700
=820
440+123+60
=500+123
=623
412+35+75
=412+110
=522
119+345+181+55
=(119+181)+(345+55)
=300+400
=700
66+34+533
=100+533
=633