Since the 1970s, the Mathematical Association of America's (MAA) journals "Mathematics Magazine" and "College Mathematics Journal" have published "Proofs without Words" (PWWs) (Nelsen 1993). "PWWs are pictures or diagrams that help the reader see why a particular mathematical statement may be true and how one…

Many ways exist to engage students without detracting from the mathematics. Certainly some are high-tech options, such as video games, online trivia sites, and PowerPoint® presentations that follow the same model as Jeopardy; but sometimes low-tech options can be just as powerful. One exciting way to connect with students is by incorporating…

One method of proof is to provide a logical argument that demonstrates the existence of a mathematical object (e.g., a number) that can be used to prove or disprove a conjecture or statement. Some such proofs result in the actual identification of such an object, whereas others just demonstrate that such an object exists. These types of proofs are…

Constructing viable arguments and reasoning abstractly is an essential part of the Common Core State Standards for Mathematics (CCSSI 2010). This article discusses the scenarios in which a mathematical task is impossible to accomplish, as well as how to approach impossible scenarios in the classroom. The concept of proof is introduced as the…

To engage students, many teachers wish to connect the mathematics they are teaching to other branches of mathematics or to real-world applications. The lesson presented in this article, which uses the algebraic skill of finding the equation of a line between two points and the geometric axiom that any two points define a line, does both. A…

While serving in the U.S. Congress, Abraham Lincoln, a self-taught learner, mastered Euclid's Elements (Basler 1953). Most students today do not study mathematics for recreation. Unlike Lincoln, they need a little help in learning how to write a geometry proof. Today's technology--specifically, The Geometer's Sketchpad[R] (GSP)--can help make…

Recognizing that textbooks play a prominent role in fostering students' understanding of reasoning and proof, the authors conducted a study to examine the extent to which textbooks used in U.S. high schools provide opportunities for students to encounter proof-related reasoning and how the nature of proof-related reasoning in textbooks varies by…

The central ideas of postcalculus mathematics courses offered in college are difficult to introduce in middle and secondary schools, especially through the engineering and sciences examples traditionally used in algebra, geometry, and trigonometry textbooks. However, certain concepts in music theory can be used to expose students to interesting…

Many students find proofs frustrating, and teachers struggle with how to help students write proofs. In fact, it is well documented that most students who have studied proofs in high school geometry courses do not master them and do not understand their function. And yet, according to NCTM's "Principles and Standards for School Mathematics"…

The purpose of this article is to present a collection of problems that allow students to investigate magic squares and Latin squares, formulate their own conjectures about these mathematical objects, look for arguments supporting or disproving their conjectures, and finally establish and prove mathematical assertions. Each problem is completed…

In this article, the author presents some interesting geometric fallacies that were used in a problem-solving course for preservice high school mathematics teachers. He states that presenting these fallacies in ordinary math classes can enrich the class by making the students think hard about both the theorems themselves and the steps in the proof…

Suggested are ways to improve the SAT and its face validity. Suggestions include greater emphasis on more-realistic problems, inclusion of realistic percent problems, modification of the multiple-choice format, and the use of the National Council of Mathematics "Curriculum and Evaluation Standards" as a guide to construct the test. (MDH)

Described are important changes that will be introduced in the mathematics sections of the new Scholastic Aptitude Test (SAT). The three main changes are (1) permission to use calculators; (2) inclusion of open-ended questions; and (3) content revisions consistent with the National Council of Teachers of Mathematics "Curriculum and Evaluation…

Presented is a summary of the actions taken by American College Testing in response to calls for reform in standardized testing. The areas of reform discussed are test development, test content, skills levels, test criteria, and new testing initiatives, such as alternative-response-format questions and calculator use. (MDH)