**FEATURES** |

Thinking and Writing Mathematically: Achilles and the Tortoise as an Algebraic Word Problem
*Joseph Martinez* Discusses author's view of word problems in an Algebra class and describes an imaginative context with a thinking and writing exercise he developed for classroom use. |

Kissing Pennies and Eating Pi
*David Buhl* A classroom inquiry into expressing pi as the limit of a sequence of different ratios using relationships among coins and the radius of an inscribed circle. |

Exploring the Birthday Paradox Using a Monte Carlo Simulation and Graphing Calculators
*Matthew Whitney* A lesson using a graphing calculator and the "birthday problem" to stimulate student interest in probability. |

Discuss with Your Colleagues: Learning Mathematical Symbolism: Challenges and Instructional Strategies
*Rheta Rubenstein, Denisse Thompson* Attempts to sensitize teachers to challenges students have with mathematical symbols, and suggests instructional strategies that can reduce student difficulties. |

Just Thinkin' of the Rain
*Charles Emenaker* A group project that involves geometry and falls into an area of mathematics known as operations research. |

Discrete Dynamical Systems Meet the Classic Monkey-and-the-Bananas Problem
*Gerald Gannon, Mario Martelli* Presents a solution to the three-sailors-and-the-bananas problem and attempts a generalization using an idea drawn from the branch of mathematics called "discrete dynamical systems." |

Centroid of a Polygon-Three Views
*Thomas Shilgalis, Carol Benson* A mathematical look at the center-of-mass concept. |

Geometric Approaches to Quadratic Equations from Other Times and Places
*Patricia Allaire, Robert Bradley* Historical solutions to quadratics problems that do not rely on symbolic manipulation. |

Pierre Varignon and the Parallelogram Theorem
*Peter Oliver* A brief biography of Pierre Varignon (1654–1722), French academician of the era of Newton and Liebniz, who furnished the first rigorous proof of the Parallelogram Theorem. |