Mathematical Fun, Games and Puzzles - Jack Frohlichstein - Google Books

http://books.google.de/books?id=w7CVzMosF-kC&pg=PA13&lpg=PA13&dq=%2216+17+18+19+20+21+22+23+24+25+26+27+28+29+30+31+48+49+50+51+

This entertaining text, developed by a math teacher, uses puzzles and games to introduce the basic ideas and operations of arithmetic. Following the standard middle school curriculum, the book presents 418 problems and 120 illustrations that cover a wide…