Having high school students prove geometrical propositions became the norm in the United States with the reforms of the 1890's - when geometry was designated as the place for students to learn the ...

I first started teaching Geometry last year and have taken over "Informal Geometry" this year. As the name of the second class implies, the idea of formal proof is strongly de-emphasized; this class ...

Educational Studies in Mathematics, Vol. 94, No. 1 (January 2017), pp. 37-54 (18 pages) This paper reports the results of an international comparative study on the nature of proof to be taught in ...