References
- President’s Council of Advisors on Science and Technology (US). Engage to excel: producing one million additional college graduates with degrees in science, technology, engineering, and mathematics. Washington (DC): President’s Council of Advisors on Science and Technology; 2012.
- Concordia Online Education [Internet]. Portland: Concordia University; c2015. History of the Classroom Blackboard; 2012 Nov 8 [cited 2015 Aug 13]. Available from: http://education.cu-portland.edu/blog/reference-material/the-history-of-the-classroom-blackboard/.
- Petrick CJ. Everybody move: learning mathematics through embodied actions [dissertation]. Austin (TX): The University of Texas at Austin; 2012.
- Gerofsky S. Mathematical learning and gesture: character viewpoint and observer viewpoint in students gestured graphs of functions. Gesture. 2010;10(2–3):321–343.
- Nathan MJ, Walkington C, Boncoddo R, et al. Actions speak louder with words: the roles of action and pedagogical language for grounding mathematical proof. Learn Instr. 2014;33:182–193.
- Mikhaylov J. Be the volume: a classroom activity to visualize volume estimation. Probl Resour Issues Math Undergrad Stud. 2011;21(2):175–182.
- Nemirovsky R, Rasmussen C, Sweeney G, et al. When the classroom floor becomes the complex plane: addition and multiplication as ways of bodily navigation. J Learn Sci. 2012;21(2):287–323.
- Wentworth GA. Elements of plane and solid geometry. Boston (MA): Ginn and Heath; 1877.
- Story WE, inventor. Spherical blackboard. United States patent US 379,914. 1888 Mar 20.
- Haynes AE. The mounting and use of a spherical blackboard. Vol. 6. Columbia (MO): Society for the Promotion of Engineering Education; 1898. p. 69–73.
- Roberts S. King of infinite space: Donald Coxeter, the man who saved geometry. New York (NY): Walker Publishing Company, Inc.; 2006.
- Austin D, Dickinson W. Spherical easel: a spherical drawing program [Internet]. c2002-2009 [cited 2015 Aug 13]. Available from: http://merganser.math.gvsu.edu/easel/
- Lénárt I. Non-euclidean adventures on the Lénárt sphere. Oakland (CA): Key Curriculum Press; 1995.
- Rybak A, Lénárt I. Comparative geometry with geogebra, spherical easel and other didactic tools. GeoGebra Int J Romania. 2012;2(2):67–76.
- Guven B, Karatas I. Students discovering spherical geometry using dynamic geometry software. Int J Math Educ Sci Technol. 2009;40(3):331–340.
- Gay D. Geometry by discovery. Hoboken (NJ): Wiley; 1997.