简便运算:1998+199.8+19.98+1.998+0.1998应该怎么算呢?

分类: 作业答案 • 2021-12-19 11:37:33

问题描述：

简便运算:1998+199.8+19.98+1.998+0.1998
应该怎么算呢?

答

1998(1+0.1+0.01+0.001+0.0001)
=2219.9778
等比数列……首项1998 公比0.1

答

1998(1+0.1+0.01+0.001+0.0001)

答

1998+199.8+19.98+1.998+0.1998
=1998(1+0.1+0.01+0.001+0.0001)
=1998*1.1111
=(2000-2)*1.1111
=2222.2-2.2222
=2219.9778

答

等比数列。。。首项1998 公比0.1