Question

1+2+3+4+5+6+7+8+9+...................+1000=?

Answer 1

=1000*1001/2

=500*1001

=500500

Answer 2

\(1+2+3+4+...+1000=\dfrac{\left[\left(1000-1\right):1+1\right].\left(1000+1\right)}{2}=\dfrac{1000.1001}{2}=500.1001=500500\)