99+99乘99+999乘999乘999的巧算 - 知识问答

99+99乘99+999乘999乘999的巧算

1个回答

=99*(99+1)+999*(1000*999-1*999)
=99*100+999*(999000-999)
=9900+999*998001
=9900+(1000-1)*998001
=9900+1000*998001-998001
=9900+(998001000-998001)
=9900+997002999
=997012899

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