On 4/9/12 8:55 PM, "Blustein, Bonnie" <BlusteB@wlac.edu> wrote:
> usage charge functions are usually step functions, actually. They round up to > the nearest full unit. > > Agreed.
In fact there are probably taxes added on that are a (possibly step) function of only parts of a bill. And fuel charges if it¹s a car rental or plane flight... Proportions, even linear (even non-linear) function modeling can only go so far, but it is still useful.
I¹m trying to think of anything in a math text that is an accurate model of a real-world situation. (not to say some of those applications should not be there)
One message I get from this is the importance of numeracy, which needs to include at least simple descriptive statistics. And an ability to read messy documents that have lots of data on them (like an electric bill).
Still, as many others have noted since Isaac Newton, it is truly wonderous that the universe behaves in ways that can be modeled with mathematics. Not artificial situations like bills, but the very laws of physics.