Didactical reflections about some proofs of the pythagorean proposition

This theoretical paper presents some dimensions considered in the literature to analyze proof in the teaching and learning of mathematics. In order to show how different types of proofs can be used with students of different levels, we use these dimensions to analyze four proofs of the Pythagorean proposition.

An investigation of the mathematical elements of the Dai culture south-west Yunnan province, China

Dai ethnic mathematical culture is an important part of Dai ethnic culture. Mathematical elements show in their daily life. Through a research project of the Yunnan Dehong Dai people in southwest China, We collected the first-hand information, tried to do a small investigative study, and collected mathematics teaching resources that is useful to primary and secondary schools students on mathematics learning  in this minority areas. Keyword: Dai ethnic; Mathematical culture; Primary and secondary schools; Teaching resources.