Outlines various subtraction methods, such as the decomposition method, equal-addends method, and low-stress algorithm. Describes a subtraction method by addition of complements. Discusses the advantages and disadvantages of the method. (YP)

Suggested activities involving number patterns, using the idea of a number machine." (MM)

The experiences described here use the idea of movement along the number line to reinforce the student's concept of addition and subtraction of both whole numbers and fractions. Four student worksheets and teacher guides are included. (MM)

Diffy" is a game designed to generate interesting drill in subtraction. it is based on the result that repeated subtraction with a cyclic sequence of whole numbers eventually produces a sequence of zeros. (MM)

The author describes an experiment to compare performance of grade 1-3 children on the various types of open sentence associated with basic number facts, and suggests some explanations for the results obtained. (MM)

A Snip of the Scissors" describes the geometry involved in making stars by paper folding, and Checking the Calculated Average Through Subtraction" suggests practice in operations with negative numbers. (MM)

The author describes various classroom activities for teaching basic number skills under the headings (1) Understanding facts, (2) Relating facts, and (3) Mastering facts. The activities are designed to involve children in the making of models of the operations of arithmetic and the interpretation of these models with number sentences. (MM)

Discusses the geometrical array of the keys on a calculator that can be turned into a problem-solving, problem-posing situation for the upper elementary or middle school classroom. Provides figures showing the arrays, including rows, diagonals, crosses, rhombi, angles, and squares. Lists seven references. (YP)

Described is a study in which three instructional approaches were applied in second grade classes. Discussed are proportional materials, nonproportional materials, nonproportional materials with pictorial models. Findings, results, and recommendations are presented. (CW)