This article focuses on spontaneous and progressive knowledge building in ''the arithmetic of the child.'' The aim is to investigate variations in the behavior patterns of eight pupils attending a school for the intellectually disabled. The study is based on the epistemology of radical constructivism and the methodology of multiple clinical…

Preschoolers made numerical comparisons between sets with varying degrees of shared surface similarity. When surface similarity was pitted against numerical equivalence (i.e., crossmapping), children made fewer number matches than when surface similarity was neutral (i.e, all sets contained the same objects). Only children who understood the…

This article presents a simple procedure to generate a sequence of rational numbers converging on the square root of 2, yielding common fraction approximations that motivate and illuminate the definition of real numbers based on rationals. Examples suggest that any irrational number can be approximated as closely as desired. A bibliography is…

Illustrates how a number system in a foreign language can be taught and learned in a cultural context. (PMP)

The major portion of the article establishes the basis for the stated rule - to divide by a fraction, turn it upside down and multiply. With this background, three justifications for the rule are given. Several possible errors in students' use of the rule are noted. (LS)

This is one of a series of units intended for both preservice and inservice elementary school teachers to satisfy a need for materials on "new mathematics" programs which (1) are readable on a self basis or with minimal instruction, (2) show the pedagogical objectives and uses of such mathematical structural ideas as the field axioms,…

The teacher's guide for the third unit of this SMSG series covers the two chapters on number theory and on the integers. The overall purpose for each of the chapters is described, the prerequisite knowledge needed by students is specified, the mathematical development of each chapter is detailed, behavioral objectives are stated, and a time…

Task cards are discussed as a tool for learning. Examples of measurement and number activities that are appropriate for task cards are given. (MP)

A sequence of numbers from combinatorial theory called the Bell numbers is discussed, along with several problems and examples that demonstrate their usefulness. (MN)

Algorithms are developed and presented for the addition and multiplication of positive rational numbers using only their repeating decimal representation. (MN)

An approach close to the original Greek geometric point of view regarding the question and proof of the irrationality of the square root of two is given. (MN)