In the winter of 1965, an experimental course in Elementary Number Theory was presented to a 6th grade class in the Hosmer School, Watertown, Massachusetts. Prior to the introduction of the present material, students had been exposed in class to such topics from the University of Illinois Arithmetic Project as lattices, number lines, frame…

Directions are given for preparing a puzzle that may be used to provide practice in computation. (MP)

Allowing students to examine different ways of performing an operation is suggested as a means of increasing their understanding. (MP)

The method described here converts a given problem in a base other than ten to a related problem in base ten, solves the related problem in base ten, and converts the answer back to the original base. Limitations are discussed. (MP)

The column presents activities for grades K-8 focusing on the concept of equality. A geometric-puzzle motif is used, with basic number facts reviewed for the lower grades and equivalent fractions for the upper levels. Four worksheets and a problem poster are included. (DT)

A teacher discusses his attempt to analyze his pupil's difficulties with arithmetic by looking at the component parts of each operation. (MP)

The use of two different colored beans or chips to represent positive and negative charges is discussed as a method of demonstrating operations with integers. (MP)

Four worksheets are designed to provide practice with addition, subtraction, and multiplication of whole numbers and decimals. (JT)

Described are two methods of calculating developed by the Dutch WISKOBAS Project: addition and subtraction with a loop abacus and multiplication using a grid model. (MP)

Magic squares are used to generate number games similar to tic-tac-toe. Skills that are reinforced include addition of negative numbers and addition and multiplication of fractions. (MP)