19+199+1999+19999+199999怎么简便算?

说清楚
2024-11-22 00:08:13
推荐回答(1个)
回答1:

19+199+1999+19999+199999

=(20-1)+(200-1)+(2000-1)+(20000-1)+(200000-1)

=222220-5

=222215