1004
Question:
The positive integers up to 2007 are alternately subtracted and added:
\[1 - 2 + 3 - 4 + \cdots + 2001 - 2002 + 2003 - 2004 + 2005 - 2006 + 2007.\]What is the value of the expression?
Answer:
Let's think step by step.

user
1004
The positive integers up to 2007 are alternately subtracted and added:
\[1 - 2 + 3 - 4 + \cdots + 2001 - 2002 + 2003 - 2004 + 2005 - 2006 + 2007.\]What is the value of the expression?
train