Can children reason the Bayesian way? We argue that the answer to this question depends on how numbers are represented, because a representation can do part of the computation. We test, for the first time, whether Bayesian reasoning can be elicited in children by means of natural frequencies. We show that when information was presented to fourth,…

A teacher in a large suburban elementary school in East Tennessee found that her fourth grade students had poor number sense and relied almost solely upon algorithmic procedure to solve math problems. Therefore, mental math was difficult for these students, so the daily number talks method was employed to strengthen number sense. However, no…

Mental arithmetic problems were presented in one of five modes to 14 fifth-grade classrooms. Results showed no significant gains in ability to use mental arithmetic or in performance on a standardized arithmetic achievement test, but gains on a problem-solving retention test and in positive attitudes. (DT)

Investigated the development of informal addition in Dioula (A Moslem ethnic group from West Africa) from childhood to adulthood and the effect of schooling on mental arithmetic. Compares these data with results from a study of children from the United States. (MK)

Suggests that strategy choice is a misleading characterization of efficient mental calculation and that teaching mental calculation methods as a whole is not conducive to flexibility. Proposes an alternative in which calculation is thought of as an interaction between noticing and knowledge. Presents an associated teaching approach to promote…

Reacts to an article published in a previous issue of this journal on the effects of graphing calculators and computer algebra systems (CAS) on students' manual calculation and algebraic manipulation skills. Considers the contribution made by Jean-Baptiste Lagrange to thinking about the role of CAS in teaching algebra. (ASK)

Students in grades 1, 4, 7, and 10 were tested in a two-part investigation of simple and complex mental addition (with college students as a reference point). One session involved a normal reaction time task in which children made true/false judgments about a series of addition examples. The other session involved a verbal protocol interview, the…

Use of an ancient method of mental calculation with aliquot parts is illustrated. Other tips for helping children reason are also included. (MNS)

The processes and procedures used by expert mental calculators are identified from a literature review. Experts are characterized by knowledge of a variety of methods, ability to recall numerical equivalents, and ability to remember the numbers involved in various stages of calculations. (MNS)

Begins with a definition of mental computation and then provides an overview of its evolution during the twentieth century. Significant benefits from teaching mental computation are highlighted, along with a framework and guidelines for instructing elementary school students. A parallel discussion is also provided for computational estimation. (RH)

This textbook's goal is to train and develop the mind by means of the science of numbers. This work is designed both for primary and advanced classes. The first part is adapted to beginners, while the latter part is peculiarly fitted to give to the more advanced student that thorough mental drilling in the analysis of numbers, which furnishes the…

This textbook's goal is to train and develop the mind by means of the science of numbers. Numbers are the instruments here employed to strengthen the memory, to cultivate the faculty of abstraction, and to sharpen and develop the reasoning powers.

Describes how students can compute and estimate, mentally and rapidly, by using appropriate number relationships. (YDS)

Three experiments attempted to clarify the effect of altering the spatial presentation of irrelevant auditory information. Previous research using serial recall tasks demonstrated a left-ear disadvantage for the presentation of irrelevant sounds (Hadlington, Bridges, & Darby, 2004). Experiments 1 and 2 examined the effects of manipulating the…

This study identified 10 savants with developmental disabilities and an exceptional ability to calculate calendar dates. These "calendar calculators" were asked to demonstrate their abilities, and their strategies were analyzed. The study found that the ability to calculate dates into the past or future varied widely among these…