This volume presents a partial description of the lessons in the preliminary version of the PLATO fractions curriculum. Each lesson has three parts: review, new material, and a student-selected option. Students receive immediate feedback from the computer as they progress through each lesson. Five groups of lessons are described: meaning of…

The introduction of prime numbers in the intermediate grades should be handled with care or the concept will appear arbitrary, artificial, and unreal to the pupils. The approach suggested here is in the form of a game-like activity. A knowledge of multiplication and factors is a prerequisite. (BB)

College students, in three experiments, learned to recite a counting pattern in the base three number system. Although all subjects learned to a criterion of two errorless trials, learning with different rule systems resulted in different levels of understanding and performance on transfer tasks. (GDC)

The emergence and differentiation of partitioning as a process that leads young children to construct ideas of rational numbers was traced through clinical sessions with 43 primary children as they manipulated objects. The data analysis led to a five-level theory of the partitioning process. (MNS)

While most elementary teachers experience little difficulty using the decimal system for whole numbers, many do not have the desired depth of understanding for teaching the system. The focus of the material is stage-by-stage creation of a hypothetical numeration system. (MP)

Children and adolescents tested to determine the development of the operator construct of rational numbers employed different problem-solving strategies depending on test presentation. Three major phases in the rational number construct appear to be a primitive fractional construct, a unit operator phase, and a general operator phase. (SB)

A visual model of fractions, the tower of bars, is used to discover patterns. Examples include equalities, inequalities, sums of unit fractions, sums of differences, symmetry, and differences and products. Infinite sequences of numbers, infinite series, and concepts of limits can be introduced. (DC)

The focus is on using the hundred chart to discover patterns, make predictions and generalizations, and visualize the number system in an organized manner. Four worksheets are on even-odd numbers (Levels 1-2), digits (Levels 3-5 and 5-6), and percentages (Levels 7-8). (MNS)

Number sense is easy to recognize but difficult to define and hence, to teach. In this article, number sense is defined in terms of the knowledge known to underline it, as identified in cognitive developmental theory and research. A preK-2 mathematics program, called Number Worlds, that was specifically developed to teach this knowledge is…

We used a numerical bisection procedure to examine preschool children's sensitivity to the numerical attributes of stimuli. In Experiment 1 children performed two tasks. In the Cups Task they earned coins for choosing a green cup after two drumbeats and a blue cup after eight drumbeats. In the Gloves Task they earned coins for raising a red glove…

This article provides activities that merge two fascinating mathematical topics: the Mayan system of numeration and magic squares. (Contains 3 figures.)

Time perception is important for many aspects of human behavior, and a large literature documents that adults represent intervals and that their ability to discriminate temporal intervals is ratio dependent. Here we replicate a recent study by vanMarle and Wynn (2006 ) that used the visual habituation paradigm and demonstrated that temporal…

Applications of a simple approximation of Bessel functions of integer order, in terms of trigonometric functions, are discussed for several examples from electromagnetism and optics. The method may be applied in the intermediate regime, bridging the "small values regime" and the "asymptotic" one, and covering, in this way, an area of great…

The Pythagorean Theorem, arguably one of the best-known results in mathematics, states that a triangle is a right triangle if and only if the sum of the squares of the lengths of two of its sides equals the square of the length of its third side. Closely associated with the Pythagorean Theorem is the concept of Pythagorean triples. A "Pythagorean…