The supplemental information provided here includes solutions for contests, contest winners, editorials, and other reader responses to our articles. We hope that you find these useful.

Issue

Electronic Material
February 2013

Famous Number Theorists by Brian D. Beasley

The solved crossword is availble here.

September 2012

270 by Chuck Wessell

Election data can be found here.

November 2010

"O, IC!" Crossword by Sam Vandervelde

The solved crossword is availble here.

September 2010

The Playground - by Derek Smith

For problem 241: Download a Mathematica notebook that provides a solution. Mathematica (version 7 or higher) is required.

April 2010

The Playground - by Derek Smith

Here is the solution to Andy Liu's cake cutting problem posed in the November, 2009 issue.

February 2010

Change for a Dollar, Change for a Million - by Martin Erickson.

This Mathematica notebook file contains all the computations performed in the article, including complete solutions to the exercises. The file ChangeForADollar.nb requires Mathematica (version 7 or higher).

The Playground - by Derek Smith

For problem 242: Download a Mathematica notebook that will allow you to flip a stack of pancakes to your heart's content. Mathematica (version 7 or higher) is required.

November 2009

Soggy Jogging - by Dank Hailman and Bruce Torrents.

This demonstration allows you to dynamically control both weather conditions and the size and shape of a 3-dimensional traveler as he runs through the rain. There are two versions. The file SoggyJoggingDemo.nb requires Mathematica (version 6 or higher). The file SoggyJoggingDemo.nbp requires the free Mathematica Player application, which is available here.

The Playground - by Derek Smith

For problem 230: Download a Mathematica notebook that will allow you to rotate and adjust the parameters for a virtual sculpture.
April 2009

Four Coloring the US Counties, by Mark McClure and Stan Wagon

Lyrics to "A Four Color Proof," by Jason Holt

The Playground edited by Derek Smith

Problem 220. Inscribe-A-Gon ended with an open question. A discussion can be found here.

Problem 221. Cutting Cake is still open. Andy Liu offers the following hint: If Alice's first cut produces two pieces of sizes 20/53 and 33/53, how should Brian respond?

Problem 229. Colorful States asks you to four-color a map. Download a nice full-page pdf version of the map here.

MATHORIZN Sudoku puzzle. Here is the solution.

November 2008
 A Dozen Questions about Pascal’s Triangle by James Tanton

Eagle eyed readers comment on some nonmathematical content. Letters are posted from Leon Harkelroad and Deborah Gray plus a short response from the author.

Perspectives on Mathematics in Art History by James Galloway

Letter to the editors from Annalisa Crannell correcting our perspective on perspective.
September 2008
 Problems and Solutions edited by Andy Liu and Derek Smith

Problem 213. Five Cubed remains open. The extensive hint promised by an editor is provided for you here. Readers are still encouraged to submit their determinations on how many different solutions are possible.
April 2008
 The Most Marvelous Theorem in Mathematics by Dan Kalman

This publication of this article purposefully coincided with two other pieces penned by the same author. Both are worth your time and energy.

The Most Marvelous Theorem in Mathematics.  Journal of Online Mathematics and its Applications, April 2008.  

An Elementary Proof of Marden's Theorem.  American Mathematical Monthly, Volume 115, Number 4, April 2008, pp 330 - 338.
September 2007
 Taking Sudoko Seriously by Laura Taalman

This article had many wonderful puzzle variations on Sudoku (Figures 9-14). The solutions are  available.  
April 2007
 Just in case you weren't sure, YES this is an April Fool's Issue.

Mathematical Enquirer (Volume 1 Issue 0, April 1, 2007)
One piece prompted the following response:
Doron  Zeilberger's Opinion 80: Shalosh B. Ekhad's Reply to the Math Horizons "April Fools" Spoof Where It Was Extensively Quoted (or Rather Misquoted)  
November 2006
 Number Theory Crossword Puzzle by Thomas P. Dence and Jenise A. Smalley
The puzzle is currently available. Solutions are finally available.
 
September 2006
 Pentominoko by Laura Taalman. Solution available.

Hidden Word Crossword and Contest by Laura Taalman.
T-shirts go to David Goldsmith, faculty member at the College of Saint Rose, David Rhee, student at McNally High School, Ross Brater, undergraduate at Ohio Wesleyan University, and Lola Thompson, undergraduate at University of Chicago for submitting the correct answer and a number closest to the randomly selected number 83. The original crossword and its solution are available.
April 2006
 Self-answering Question Contest---Winning entries from September 2005 contest. Plus the Mathematica code to verify entry by Tupper and Wagon and even more self-answering questions for your enjoyment.
February 2006

Links to some of our artistic authors. 

George Hart

 Sculpture

Robert Bosch

 Domino Art

Thomas Hull

 Origami Mathematics

Larry Lesser

 Mathemusican

Gwen Fisher

 Beaded Beads

Hidden Word Crossword and Contest by Laura Taalman.
Submit your solution for fabulous prizes by April 15, 2006.
 
November 2005
A (Mostly) Differential Equations Crossword Puzzle by Thomas Dence, Jenise Smalley, and Kenneth Gasser
The puzzle and solution are available.

Thanks to everyone who participated in the online Math Horizons survey. Special congratulations go to senior mathematics major Brian Worthen from Bryan, Texas. He was randomly selected from all the participants to receive five free MAA books!
 
September 2005
 Mathematical Inversions---Winning entries from November 2004 contest.

Liars and Truthtellers: Learning Logic from Raymond Smullyan by Robert L. Holliday
Additional puzzles and solutions for your enjoyment. 

The Virginia Tech Regional Math Contest by Peter A. Linnell
The question from a previous VTRMC and its solution are available.

Self-answering Question Contest by Chris Hill
Submit your entry (both question and answer!)
 
April 2005
 Playing with Matches by Eric Libicki
Questions and answers available.
 
February 2005 
 A reader response to Stuart Boersma's article A Mathematician's Look at Foucault's Pendulum. It gives a simpler geometric derivation of the same result and would be suitable for discussion in an undergraduate or even high school math class. The result is one of those delightful "AHA!"s that make mathematics so much fun.

A Comment on Stuart Boersma's article "A Mathematician's Look at Foucault's Pendulum" by Greg Johnson (posted June 2005)

Self-Referential Aptitude Test by Jim Propp  
Questions and answers available.
 
September 2004
 Biography of a Contest Problem by Steven Dunbar & Kevin Hankin
Solution to regular n-pointed star problem.
 
April 2004
 Analysis Word Search  by Thomas Dence, Ken Gasser, Jenn Meyer, & Jenise Smalley
The puzzle and solutions are available.
 
November 2002
 A reader response to The Devil is in the Culture by sarah-maria belcastro with Aaron Howard. It gives a different perspective on Enzensberger's The Number Devil and provides some insight on the original German.

"Personal Refections on The Number Devil" by Angie Thuy-Anh Mai (posted June 2005)
November 2000
 The Final Exam: World Wide Web Treasure Hunt — solutions and winners!
April 1999
 The Final Exam: Pi Mnemonics  — winning entry!
February 1999
 The Final Exam: Who Said It? — solutions.