Discussed is a way of playing with numbers that leads to interesting results and provides well-disguised drill. (JP)

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)

The author examines a well known number trick, in other number bases, and finds that equivalent results arise. (CT)

The article reviews the development of mathematics error analysis as a means of diagnosing students' cognitive reasoning. Errors specific to addition, subtraction, multiplication, and division are described, and suggestions for remediation are provided. (CL)

This experiment involved 176 London children aged six and seven. Their levels of attainment on subtraction were quickly and accurately established by two questions. Then teaching programs were used to help them attain prerequisite skills. To symbolize too soon is a danger to be avoided. (MNS)

Two screening questions developed in the study were viewed as invaluable diagnostically and seen as possible immediate value to teachers. The questions were used to group subjects into three different levels. Two instructional programs were developed. One was for the lowest two levels, the other for the highest group. (Author/MP)

Drill activities for addition, subtraction, multiplication, and division that are derived from the history of mathematics are suggested. (MK)

Children, 9-11 years old, solved subtraction problems in the form of M-N=..., then gave a verbal report on the thought processes used, analysis of which utilized a model based on analyses of reaction times, and resulted in a more detailed process model. (AN)

Novel practice exercises for addition and subtraction using a special number puzzle called a number chain are suggested. (MK)

An experimental program using the calculator in third, fourth, and fifth grades is described. Three example lessons are included, on (1) subtraction with regrouping, (2) estimation, and (3) number theory: Quadratics. (MK)

This study was implemented to test the relative effectiveness of two subtraction procedures (decomposition and equal addends) with respect to accuracy in solving subtraction problems requiring regrouping. Results favor the decomposition approach. (MP)

The importance of place value is discussed. Examples illustrating place value in addition and subtraction are given. (MK)