When the focus of instruction is on learning to use mathematical tools--such as a ruler or a calculator--as a procedure, students tend not to incorporate their own mathematical reasoning. This unreflective use of tools hinders students' questioning of the reasonableness of their answers. This article describes how children expressed their…

Engaging students with real-world activities can be effective in supporting the learning of mathematics, "whenever possible, real-world situations will provide a context for both introducing and applying geometric topics" (NCTM 1989). Tool making is a way to bring real-world mathematics into the classroom and using the tool is a way of…