(1)
2002+2001-2000-1999+1998+1997-1996-1995+.+2+1
=2002+(2001-2000-1999+1998)+(1997-1996-1995+1994).+(5-4-3+2)+1
=2002+0+0+……+0+1
=2003
(2)原式=1+1/2-1/2-1/3+1/3+1/4-1/4-1/5+1/5+1/6-1/6-1/7+1/7+1/8
=1+1/8
=9/8
(3)原式=1-1/2+1/2-1/3+……+1/9-1/10+1/10-1/11
=1-1/11
=10/11
(4)原式=(1+2+……+1882)/1883
=1/2*(1882+1)*1882/1883
=941