Makeuseof.com has instructions on how to cut down the amount of paper we use by Printing Multiple Pages On One Sheet. With so many documents 10, 20, 30 or more pages long, there's no reason we can't print more than one page on each sheet, cutting the amount of printing into half, thirds, or more. Here are some easy instructions for PC's or Mac's:
PC (Word 2007):
Click the Office button => Print => Select the dropdown menu under Zoom and select the number of pages per sheet.
MAC:
command + p => select the lowest dropdown menu and click layout => select pages per sheet.

