(1+3+5+······2013)—(2+4+6······+2014)
=1+3+5+······+2013-2-4-6-······-2014
=(1-2)+(3-4)+(5-6)+……+(2013-2014) [共有1007组]
=(-1)+(-1)+(-1)+……+(-1) [共有1007个(-1)相加]
=(-1)×1007
=-1007
(1+3+5+······2013)—(2+4+6······+2014)
=1+3+5+······+2013-2-4-6-······-2014
=(1-2)+(3-4)+(5-6)+……+(2013-2014) [共有1007组]
=(-1)+(-1)+(-1)+……+(-1) [共有1007个(-1)相加]
=(-1)×1007
=-1007