Real World Problems

I’ve been shopping for a new cell phone (doesn’t yours have an antenna?) and it reminded me about cell phone plans and linear algebra.

Cell phone plans used to be the prototypical real world problem for high school math classes.

Plan A costs $10 a month plus 25 cents a minute, while Plan B costs $30 a month plus 12 cents a minute.  Which plan should Sue Consumer choose?

Figure out the equations of some lines, find the intersection, make some conclusions.  Math in action!

Fast forward to the present, and it’s embarrassing how confused I am by all the options:  a serious multivariable analysis is necessary to figure out which plan is the right one for me.  This was once an exemplar of simple, relevant application, but now it has become ugly with the real real world details.