A Discussion on Mathematical Connectedness of Pi(π) in School Mathematics

The 16th Greek alphabet π being a kind of ‘numeral’ as the letter or symbol used to represent a mathematical constant, the ratio of the circumference of a circle to its diameter, the ‘length’ of the circumference and the ‘area’ of a circle with radius 1, the ‘angular measure’ of straight angle, the ‘proportional constant’ of direct proportion y/x=π , the ‘slope’ of the graph of linear function y=πx, a ‘mathematical invariant’ of circle representing the similarity of all circles, and so on is connected with several mathematical concepts and has several meanings. In this paper we investigate those several meanings of π with reference to several mathematical concepts in school mathematics and discuss how to improve teaching and learning of those concepts and π in view of mathematical connectedness of π