Original: Before it ceased operating, Nupedia produced 24 articles that completed its review process (three articles also existed in two versions of different lengths), and 74 more articles were in progress.
Simplified: By the time the site was closed in September 2003, there were 24 articles on Nupedia, with another 74 articles ready to be made. When Wikipedia took over, the articles from Nupedia were moved there, and those were the first articles of Wikipedia.