Buy the entire set of Ed Zaccaro math books and save $50.00. Regular (non-spiral bindings only).  

Books include:  Primary Grade Challenge Math  Challenge Math for the Elementary and Middle School Student  Real World Algebra  Becoming a Problem Solving Genius: A Handbook of Math Strategies  The 10 Things All Future Mathematicians and Scientists Must Know (But are Rarely Taught)  25 Real Life Math Investigations That Will Astound Teachers and Students Scammed by Statistics: How We are Lied to, Cheated and Manipulated by Statistics...and Why You Should Care Upper Elementary Challenge Math Entire set ships for minimum shipping charge of $4.95.