用简便方法运算 999×999+1999 873-215-173-185.

2025-02-24 00:16:27
推荐回答(1个)
回答1:

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

(2)873-215-173-185
=(873-173)-(215+185)
=700-400
=300