People tend to underestimate subtraction and overestimate addition outcomes and to associate subtraction with the left side and addition with the right side. These two phenomena are collectively labeled 'operational momentum' (OM) and thought to have their origins in the same mechanism of 'moving attention along the mental number line'. OM in…

Adults' simple arithmetic performance is more efficient when operands are presented in Arabic digit (3 + 5) than in number word (three + five) formats. An explanation provided is that visual familiarity with digits is higher respect to number words. However, most studies have been limited to single-digit addition and multiplication problems. In…

Subtractions of the type M - S = ? can be solved by various strategies, including subtraction by addition. In this study, we investigated children's use of subtraction by addition by means of reaction time analyses. We presented 106 third to sixth graders with 32 large non-tie single-digit problems in both subtraction (12 - 9 = .) and addition…

The author attempts to obtain some new evidence on simple addition processes in adults in order to evaluate the two additon models offered by Groen and Parkman (1972); a simple counting model and a more complex retrieval model, involving direct access and counting. (Author/RK)

Sixty-four adults were tested on simple addition and multiplication problems presented in Arabic digit or English number-word format. Overall, response times and error rates were much higher with the word format, but more important, presentation format interacted with arithmetic operation and problem size. (DR)

This report describes a simulation of adults' retrieval of arithmetic facts from a network-based memory representation. The goals of the simulation project are to: demonstrate in specific form the nature of a spreading activation model of mental arithmetic; account for three important reaction time effects observed in laboratory investigations;…

A computer model of memory (based on input, retrieval, and reaction time) was applied to the rapid processing of simple arithmetic facts (addition, subtraction, and multiplication) by 18 educable retarded adolescents when compared with 18 nonretarded fourth graders (of equal mental age) and 18 normal adolescents. Results for addition indicated…