Developers of free math worksheets primarily use either of two methods for displaying and printing worksheets on the Internet. PDF pages require an additional piece of software, Adobe Acrobat, which should automatically open worksheets in your browser. PDF worksheets theoretically cannot be manipulated and display/print precisely as the developer designed. The second mode of delivery, HTML code, displays worksheets directly in your browser window. The downside of using HTML based worksheets is they are prone to printing problems. A worksheet meant for one page can easily bleed over to a second sheet.
Books _ Among the dozen or so math word_problem books of note published in the past decade, one, written by Mary Jane Sterling, from a well_known, popular brand of information books, which I'm unable to name here, stands out. The publisher has put a decent chunk of the book online at books.Google.com (go to books.google.com and search for sterling word problems).