Why does typing rand(100,60) into Microsoft Word result in it creating 81 pages?

I have a very simple Office utility question.

Open Microsoft word (2003 or 2007), whatever you use.

• Let's have a new empty blank document (it's up to you to have it or not)
• Press enter to go to a new line
• now type "=rand(100,60)" in new line
• Now press enter
• After writing this - it will create 81 pages long story

The question is what exactly is Microsoft Word doing?

This is a known feature.

100 is the number of paragraphs; 60 is the number of sentences per paragraph.