This clarification is not for the expert, but the novice. The specialized use of the term variable should not the first one given in an algebra text or dictionary, mathematical or not. Variables Without Symbols We can talk about numbers and quantities, and among them identify those which are changing or varying, and those which are constant, known, unknown, given, confidential and so on. Here a number and quantity which may vary or take many values in the circumstances of interest is called a variable . We can talk about variables without using the shorthand notation, that is, letters and symbols, employed in algebra.
Formulas use shorthand notation, that is symbols or letters, to represent numbers and quantities.
This suggests when a symbol or letter is the shorthand notation for a number or quantity which may vary, we will also call that symbol or letter a variable . The common idea that all variables have to be given by letters has misled many. The notion of a variable can be understood before the use of algebraic notation or symbols in mathematics. 1 Introduction 2. Ski Trails 3 Sign Analysis 4.