§奥数①(简单的类型)(1)2005×20062006-2006×20042004=_____(2)2005.0514+

(1)2005×20062006-2006×20042004
=2005×2006×10001-2006×2004×10001
=2006×10001×(2005-2004)
=20062006
(2)2005.0514+2004.0515-2003.0516-2002.0517+2001.0518+2000.0519-1999.0520-1998.0521+……+1521.0998
= (2005.0514-2003.0516)+(2004.0515-2002.0517)+(2001.0518-1999.0520)+(2000.0519-1998.0521)+……
=1.9998+1.9998+……
=(2-0.0002)×242
=484-0.0484
=483.9516

(1)=20052006
(2)

第一题用乘法分配律，结果等于20062006
过程自己琢磨吧！！