A mathematical constant is a number that is independent of physical measurement, and exist naturally in mathematics. Pi is an example of a mathematical constant.
http://answers.ask.com/Science/Other/what_is_a_con...

As a noun, a term or expression with no variables. Also, a term or expression for
http://www.chacha.com/question/whatisaconstant...

If two variables, X and Y, are linked by a relationship according to which. X = 0 when Y = 0 (and conversely) and. a unit change in X results in a change in Y of k units (either always
http://wiki.answers.com/Q/What_does_constant_of_pr...

A simple example of a constant rate is a car with cruise control set at 60 mph. You know that in 10 minutes you have traveled 10 miles and that in 30 minutes you have traveled 30
http://www.ehow.com/info_10057980_constantratema...
