On Jan 25, 8:52 pm, eratosthenes <rehamkcir...@gmail.com> wrote: > Hi all. > > I am currently tutoring at a community college and one of my students > is a sixth grade teacher going back to school because she needs a > calculus credit to complete her certification or something, but that > is beside the point. > > She asked me if I could give her a way to explain what a mathematical > function is to a sixth grader other than the standard explanation > about it being a machine that you put one number into and receive > another out of. She said that this does not work. > > I tried explaining how I learned long ago: As a map where the > equation is the directions or something like that. She was also > dissatisfied with that. > > Any thoughts? > > Patrick
If f: R -> R, where R is a real line, then thinking of f as a machine that you put one number into and receive another out is adequate. In fact, I can't think of anything better than that. There may be some simple formula associated with matching the input with the output, or not. I don't know if they also need to know what is injection, surjection and bijection, but that comes after the basic definition.