The effects of whole number computation interventions among school students with learning disabilities in Grades K to 5 were examined using a multilevel meta-analysis. Applying a correlated and hierarchical effect model of robust variance estimation, we examined the intervention effects among 15 peer-reviewed articles and dissertations (two…

Mixed numbers and fraction in general have been a problem for students not only in understanding the concept of itself, but also in understanding the operation of it, such as addition. Thus, supporting students in learning addition of mixed numbers is needed. The aim of this study is to develop a local instructional theory and materials related to…

This study examined interventions for addition and subtraction that were implemented through single-case design (SCD) research studies. We attempted to extend prior SCD meta-analyses by examining differences in effect sizes across several moderating variables and by including a novel index of effect, improvement rate difference (IRD). We also…

The 2011 study, "Benefits of Practicing 4 = 2 + 2: Nontraditional Problem Formats Facilitate Children's Understanding of Mathematical Equivalence," examined the effects of addition practice using nontraditional problem formats on students' understanding of mathematical equivalence. In nontraditional problem formats, operations appear on…

Understanding the meaning of rational numbers and how to perform mathematical operations with those numbers seems to be a perennial problem in the United States for both adults and children. Based on previous work, we hypothesized that giving students more time to practice using rational numbers in an environment that enticed them to apply their…

Developing concepts, modeling, and solving problems form the core of essential learning about addition and subtraction. That educators may make the task more difficult than necessary is the thrust of several recent studies. Highlights from these studies (with suggestions for instruction) are presented. (JN)

This paper is concerned with the role of meaning and understanding in the acquisition of computational skill in subtraction. Evidence on the syntactic nature of subtraction errors is reviewed, with common "bugs" described. Then, data collected from interviews with four children are summarized in terms of their semantics of concrete…

Fifty Brazilian children aged seven-13 were individually given addition and subtraction exercises. Counting was the preferred procedure, with use of school-taught algorithms limited. Some children decomposed numbers into tens and units and then worked at both levels. They rarely referred to previous results when doing related exercises. (MNS)

Use of the commutativity, addition-subtraction complement, and N+1 progression principles was studied by interviewing 54 capable pupils in grades 1-3. Commutativity was used extensively at each grade, while the addition-subtraction principle to solve subtraction varied across grades, and the N+1 pattern was seldom used. (MNS)

Reviews research using diagrams, number sentences, and algorithms to help students learn to add and subtract; poses questions on the relationship of instruction to children's knowledge construction; and proposes a research agenda in this area. (86 references) (MKR)

A sample of 24 subjects was presented with 800 addition problems to test a general model of simple and complex addition. According to this model, an addition problem is encoded and verified by column, with specific addition strategies determined by the size of the problem. Two hundred problems each of the following four types were presented: (1)…

This study involved 48 students ages 9 to 12. The 29 experimental group students, divided into small groups, performed learning exercises designed to improve skills in analyzing and processing expressions frequently included in addition and multiplication problems. The exercises helped significantly to improve problem-solving performance. (MNS)

The primary objective of this study was to provide an experimental model of children's representations of addition and subtraction concepts viewed as constructed schemes. How children with different counting schemes differ in their addition and subtraction concepts and how the types of problems children solve correlate with the addition and…

This study was an attempt to provide some evidence on the effects of calculator usage with primary-age children. Specifically, the study compared the performance of children who had access to calculators for an extended period of time, and whose teachers used calculators in specified instructional ways, with children who did not have access to…

This study involved 179 9-year-olds and 352 13-year-olds in New Zealand. Four addition and four subtraction tasks were set to ascertain students' ability to use the number line. Comparison of these data with results from the national assessment in the United States are given. (MNS)