Manipulatives offer students with disabilities access and support in classrooms. However, it is important for educators to be aware that concrete manipulatives are not the only option. Teachers serving students identified with a disability in the middle grades may consider selecting virtual manipulatives as supplement, complement, or in lieu of…

The virtual-representational-abstract (VRA) framework adapts an evidence-based practice, the concrete-representational-abstract (CRA) framework, while trying to meet students and teachers where they are in terms of technology interest and use in education. This article discusses the VRA framework and the advantages of virtual manipulatives, and…

What does it mean for teachers to integrate technology effectively? Effectively integrating technology means teaching "with" not "near" technology. The author defines "teaching near technology" (Leatham 2002) as using technology in a manner that does not promote opportunities for students to communicate, reflect, and…

Today technology allows for the utilization of new classes of mathematical objects which are themselves subject to new modes of student interaction. A series of notable examples may be found in the National Library of Virtual Manipulatives. These virtual manipulatives draw much of their power from their physical embodiment in the form of hand-on…

Previous work covers building a tower from a stack of homogeneous rectangular plates, each with a maximum shift in displacement. We suggest using plates shaped as curvilinear triangles bounded by segments of power-law functions. The masses of the plates and the position of their center of mass are calculated and measured experimentally after…

In the criminal justice system, defendants accused of a crime are presumed innocent until proven guilty. Statistical inference in any context is built on an analogous principle: The null hypothesis--often a hypothesis of "no difference" or "no effect"--is presumed true unless there is sufficient evidence against it. In this…

To create an environment in which all students have opportunities to notice, describe, and wonder about variability, this article takes a context familiar to many teacher--sampling colored chips from a jar--and shows how this context was used to explicitly focus on variation in the classroom. The sampling activity includes physical as well as…