Answer
500497
Work Step by Step
The sum of the first n integers is given by:
1 + 2 + ··· + n = $\frac{n(n+1)}{2}$
3 + 4 + 5 + 6 + ··· + 1000
= (1 + 2 + 3 + 4 + ··· +1000) − (1 + 2)
= $\frac{1000\times(1001)}{2}$ -3
=500500 - 3
= 500,497