9999×7778+3333×6666
= 9999×7778+3333×(3×2222)
= 9999×7778+9999×2222
= 9999×(7778+2222)
= 9999×10000
= 99990000
望采纳——————》》
动脑筋：9999*7778+3333*6666 用简便方法计算,最后得数是99990000
9999×7778+3333×6666
= 9999×7778+3333×(3×2222)
= 9999×7778+9999×2222
= 9999×(7778+2222)
= 9999×10000
= 99990000
望采纳——————》》