How Many Ways to Solve this Problem? Add the Sequential Numbers x Through y

July 13, 2011 I am not entirely sure why, however a couple of days ago the following search keywords were used to access one or more articles on this blog: the sum of 1+2+3+4...+98+99+100 The above request I found to be a bit interesting, and there is a 50/50 chance that the person found the right answer [...]