计算:1-2+3-4+5-6+…+2001-2002+2003-2004.

问题描述:

计算:1-2+3-4+5-6+…+2001-2002+2003-2004.

1-2+3-4+5-6+…+2001-2002+2003-2004
=(1-2)+(3-4)+(5-6)+…+(2001-2002)+(2003-2004)
=-1-1-1-1-…-1-1
=-1×(2004÷2)
=-1×1002
=-1002