I tried to make that part of the original rules...that you have to say something, but no one did it : ( I think it would make it more fun. *nodnods*
In the next version you should make them have to include the new number in a sentence somewhere.
Like "I'm holding seventy three pencils right now!" No digits, written out. That would create a more interesting battle. And put a shorter page limit. Like 100 pages or something.
Just throwing ideas out there.