344865
Explanation
Use the following formula:
[tex]\sum ^n_{i=1}i=\frac{n(n+1)}{2}[/tex]
In this case, n=830, thus you get your answer by entering 830 in the formula like this:
[tex]\begin{gathered} \sum ^n_{i=1}i=\frac{n(n+1)}{2} \\ \sum ^{830}_{i=1}i=\frac{830(830+1)}{2} \\ \sum ^{830}_{i=1}i=\frac{830(831)}{2} \\ \sum ^{830}_{i=1}i=\frac{689730}{2} \\ \sum ^{830}_{i=1}i=344865 \end{gathered}[/tex]so, the answer is
344865
