I present a viable learning trajectory for prospective elementary teachers' number sense development with a focus on whole-number place value, addition, and subtraction. I document a chronology of classroom mathematical practices in a Number and Operations course. The findings provide insights into prospective elementary teachers' number sense…

This article contributes to the research literature concerning prospective elementary teachers' mathematical thinking and learning with a focus on flexibility. We present a case study of a prospective elementary teachers' development of flexibility in mental addition and subtraction during a Number and Operations course. Building upon the…

Achieving fluency with basic subtraction and add-with-8 or -9 combinations is difficult for primary grade children. A 9-month training experiment entailed evaluating the efficacy of software designed to promote such fluency via guided learning of reasoning strategies. Seventy-five eligible first graders were randomly assigned to one of three…

The aim of the study was to analyze the development of children's adaptive expertise in computing sums and differences up to 100. We defined the adaptive nature of children's strategy choices on the basis of problem (addition, subtraction), achievement, and strategy performance (accuracy, speed). Sixty-nine 2nd graders of high, above-average, or…

Analyzed conceptual and linguistic complexities of matching situation word problems. Found a four-level progression in conceptualizing and solving these problems: Relational ("who had more/less" but not "how much more/less"); Language Cue (equalizing or compare language); Understand Matching Situations (difference between two…

Interviewed 70 children learning multidigit addition and subtraction in 2 different learning environments. Found that understanding and skill were closely related for tasks in which students had received no instruction and on more difficult tasks even after instruction. The alternative instruction, which encouraged students to develop their own…

Examines the hypothesis that problem comprehension and computational processes interact during the solving of arithmetic word problems. Results suggest the absence of any interaction between the two processes. Questions the notion that automatized retrieval facilitates problem solving, as well as assertions suggesting that increasing computational…

Two studies pursued theory that knowledge of addition combinations facilitates learning of subtraction combinations. Study 1 involved 25 kindergartners and 15 first graders in a gifted program; study 2 involved 21 first graders in a regular program. Participants responded to two pairs of problems. Findings revealed that the complementary…

Two experiments examined the use of a number-line metaphor presented with interactive multimedia to help sixth graders with varying levels of mathematics achievement or spatial ability build connections between addition and subtraction of signed numbers and existing conceptual knowledge. Results indicated that use of multiple representations…