用简便方法计算下面各题. (1)677+3×6770+677×69 (2)1999+999×999.

如题所述

第1个回答  2022-07-29
(1)677+3×6770+677×69,
=677+30×677+677×69,
=677×(1+30+69),
=677×100,
=67700;

(2)1999+999×999,
=(1000-1)×999+1999,
=999000-999+1999,
=999000+1000,
=1000000.
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