The method used by Cantor to demonstrate the uncountability of the real numbers is applied to a proof showing that the set of natural numbers is uncountable; the error in the argument is discussed. (DT)

This classroom note includes the following sections: Introduction; The General Case; and Related Formulas.

Authors use combinatorical analysis to prove some interesting facts about the Fibonacci sequence.

The paper details a comprehensive system for the treatment of the topic of limits--conceptually, computationally, and formally. The system addresses fundamental linguistic flaws in the standard presentation of limits, which attempts to force limit discussion into the language of individual real numbers and equality. The system of near-numbers…

Although many studies have examined the alignment of state standards with large-scale assessment and instruction, fewer have attended to alignment concerning alternate assessments for students with significant disabilities. This study was designed to (1) compare expectations in one state's alternate assessment (AA) with curricular priorities…

Simplicity in number naming in a language (e.g. "ten-two" in Chinese is simpler than the irregular "twelve" in English) has been used to explain cross-cultural disparities in children's computational competence. In contrast to previous research focusing only on whether children can provide the correct answers, in this study (N =117 and 92) we…

In the renewed "Primary Framework for Mathematics" for England, great emphasis is given to calculation and its prerequisites (DfES, 2006). Expectations are increased for calculations and the recall of number facts, with mental calculation owning a higher profile, while progression in written calculation is clarified. The greater focus on…

Illustrated is the use of arithmetic modulo 2 for finding the truth values of logical statements. (MM)

Divisibility tests for digits other than 7 are well known and rely on the base 10 representation of numbers. For example, a natural number is divisible by 4 if the last 2 digits are divisible by 4 because 4 divides 10[sup k] for all k equal to or greater than 2. Divisibility tests for 7, while not nearly as well known, do exist and are also…

In this article, the author believes that a visual image of the number system is helpful to everyone, especially children, in understanding what is, after all, an abstract idea. The simplest model is the number line, a row of equally spaced numbers, starting at zero. This illustrates the continuous progression of the natural numbers, moving to the…