Describes a knowledge-based tutoring system which provides pupil interaction with the microcomputer to diagnose pupils' errors in subtraction operations. Current subtraction methods; nature and origin of subtraction errors; and the structure, achievements, and future developments of the computer system are included. Thirteen references and a…

A model of subtraction development and the computing difficulties and research issues suggested by the model are outlined. Demands of simultaneous processes, difficulties with informal subtraction, and the impact on the counting-up procedure are discussed. (MNS)

Discusses four ways in which subtraction is more difficult than addition: (1) verbal solutions do not always parallel object solutions; (2) methods may interfere with each other; (3) special problems exist with subtraction on the number line; and (4) subtraction has multiple situational interpretations. (MNS)

Four ideas are presented, each a variation of the tic-tac-toe game. Recognizing three addends is the goal of the primary level game; experiences with basic facts and fractions are objectives for upper levels. Each worksheet includes objectives, directions, and comments. (LS)

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)

It is noted that defining subtraction independently of addition through use of physical objects can help one to illustrate the non-commutativity of this operation. Lack of awareness of the importance of the order of the digits may be a primary cause of errors in compound subtraction. (MP)

A modification to the ancient game of NIM is promoted which can provide a set of games seen as suitable for promoting practice in subtraction and simple strategy formation for a range of pupils in both the primary and secondary grades. The game versions noted are normally for two players. (MP)

A subtraction algorithm that does not involve borrowing is presented and called the residue method. It has been taught in junior and senior high school classes and preservice and inservice classes for teachers. The method has helped in classes where arithmetic in other bases is presented. (MP)

Activity sheets and gameboards for basic addition and subtraction practice, regrouping, and estimating are presented. (MP)

An analysis is presented of pupil responses to several items on the second National Assessment of Educational Progress (NAEP) mathematics survey which focused on the concepts and models of the fundamental operations. (MP) Aspect of National Assessment (NAEP) dealt with in this document: Results (Interpretation).

Three differences between the mathematics training of students from Spanish-speaking countries and that typical for pupils in the United States are discussed. (MP)

Practical tips on the teaching of subtraction, addition and subtraction of fractions, and finding the vertex of a parabola are given. (MK)

Describes a study that investigates the subtraction skills of primary students (N=65) in two schools. Students solve tasks and explain procedures and their teachers are interviewed to determine their objectives and strategies. Contains 41 references. (DDR)

Presents an issue that arises in every country: How can teachers best help children master basic addition and subtraction facts? Discusses how this is handled in China and highlights the impact that language has on how children think about numbers. (KHR)

The grade placement of topics in addition and subtraction was compared across the five countries through analysis of textbooks. "Remarkable" uniformity in grade placement was noted for Japan, China, the Soviet Union, and Taiwan, but the United States differed substantially. (MNS)