This is a critical review of surveys conducted on the American deaf population since 1990. There is no agreement among the surveys on the number of deaf and hard of hearing individuals in the US. This behooves us to study the question: Why the lack of agreement in estimates and prevalence rates of the American general deaf and the deaf child…

The arithmetical performance of typically achieving 5- to 7-year-olds (N=29) was measured at four 6-month intervals. The same seven tasks were used at each time point: exact calculation, story problems, approximate arithmetic, place value, calculation principles, forced retrieval, and written problems. Although group analysis showed mostly linear…

The cognitive processes underlying quantitative estimations vary. Past research has identified task-contingent changes between rule-based and exemplar-based processes (P. Juslin, L. Karlsson, & H. Olsson, 2008). B. von Helversen and J. Rieskamp (2008), however, proposed a simple rule-based model--the mapping model--that outperformed the…

The hierarchical competing systems model (HCSM) provides a framework for understanding the emergence and early development of executive function--the cognitive processes underlying the conscious control of behavior--in the context of search for hidden objects. According to this model, behavior is determined by the joint influence of a…

A problem addressed infrequently in beginning physics courses is that of a moving body with changing mass. Elementary texts often have footnotes referring to jet planes and rockets but rarely do they go further. This omission is understandable because calculations with variable mass generally require the tools of calculus. This paper presents a…

We discuss the identification, estimation, and testing of structural equation models that have causal indicators. We first provide 2 rules of identification that are particularly helpful in models with causal indicators--the 2C emitted paths rule and the exogenous X rule. We demonstrate how these rules can help us distinguish identified from…

Visualizing complex roots of a quadratic equation has been a quest since the inception of the Argand plane in the 1800s. Many algebraic and numerical methods exist for calculating complex roots of an equation, but few visual methods exist. Following on from papers by Harding and Engelbrecht (A. Harding and J. Engelbrecht, "Sibling curves and…

The statistic of choice to prove that U.S. schools are failing has changed over time. First, it was test scores that meant they could not keep up with Japan. More recently it has become graduation rate. Often accompanying the graduation rate in the failure litany is the drop-out rate. NCLB puts additional pressure on dropout counts because it…

This paper estimates the elasticity of taxable income to the net-of-tax share using a panel of tax returns that follows a random sample of taxpayers from 1999 to 2005, spanning the EGTRRA 2001 and JGTRRA 2003 tax changes. Results suggest that the elasticity of taxable income to the current year's net-of-tax share lies between 0.3 and 0.4 overall,…

In this article, the author shares how his fourth-grade students' creative thinking concerning a long-standing research problem stimulated changes in his instructional strategies. He begins by providing an example which illustrates that the standard tool of democracy, the plurality vote, suffers serious deficiencies: "The winner can be the…

In this activity, students will develop an understanding of the economic impact of technology by estimating the cost savings of power management strategies in the classroom. Students will learn how to adjust computer display settings to influence the impact that the computer has on the financial burden to the school. They will use mathematics to…

By providing early, individualized estimates of college costs and financial aid, net price calculators can help prospective college students and their families look past often scary "sticker prices" and start figuring out which colleges they might be able to afford. These online tools, currently available on almost all college websites, can help…

This study addressed predictors of the development of word problem solving (WPS) across the intermediate grades. At beginning of 3rd grade, 4 cohorts of students (N = 261) were measured on computation, language, nonverbal reasoning skills, and attentive behavior and were assessed 4 times from beginning of 3rd through end of 5th grade on 2 measures…

According to this author, when it comes to data-based decision making, many educators are looking in the wrong place. This is one reason why this potentially powerful practice has too often under-delivered. Many schools rush headlong into analyzing data without considering if the data they are reviewing is worth the effort, if other data might…

For students and their families, deciding whether and where to go to college is one of the most important financial decisions they will ever make. However, unlike buying a computer, house, or car, most prospective students do not know how much it will cost them to attend a particular school until many of their choices about college have already…