Question

9.9＋99.9＋999.9＋9999.9＋1简便运算

Answer 1

我来回答你：

9.9＋99.9＋999.9＋9999.9＋1

＝(10-0.1)+(100-0.1)+(1000-0.1)+(10000-0.1)+1

=11111-0.1*4

=11110.6

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