A one-degree angle would certainly be difficult to draw accurately, especially without the aid of other tools like a protractor. However, mentally making a one-degree angle in visualized imagination is not only possible, but it is important for students' emergent understandings of angular measure. When students begin learning about length,…

We present results of a grounded analysis of individual interviews in which students play Vector Unknown -- a digital game designed to introduce visualizing vectors, scaling vectors, vector addition, and vector equations, attending to the geometric and algebraic representations of vectors. The game was designed to be used at the beginning of a…

Design activities help students develop their three-dimensional thinking skills and gain engineering and technology literacy. This study investigated whether the spatial abilities and 3D geometrical thinking skills of the students differed according to approaches to learning mathematics before and after engineering design-based mathematics (EDBM)…

This study surveyed and analysed four secondary school students' writing about a square. Sfard's discursive approach to understanding mathematical discourse was used to analyse the responses collected from 214 Australian secondary school students. The results showed that geometric knowledge was developed experientially and not developmentally.…

Surface area is consistently identified as a curriculum standard for K-12 students and it regularly appears on national and international assessments. Recently, many schools began acquiring digital fabrication and advanced manufacturing equipment. The growing use of digital fabrication in classrooms raises the question of whether or not this…

Describes a method for teaching Euler's line, the co-linearity of the circumcenter, centroid, and orthocenter of a triangle. Discusses teaching results. (KHR)

Presents a teaching experience with high school students in geometry class using hand signals that reinforce meaning of geometric concepts. (KHR)

Discusses underlying mental processes for understanding volume measurement. Presents an instructional activity that promotes students' structuring of three-dimensional arrays of cubes and the electronic version of the "How Many Cubes?" activities. Includes student activity sheets. (KHR)