On the block schedule students take four classes at a time and grades are reported every nine weeks.

On the block schedule students take four classes at a time and grades are reported every nine weeks.  Suppose in the 7th grade you convinced your parents to give you 1 cent for every A on your report card and double that every time report cards came out until you graduated.  If you made all A’s all the way through, how much would the last grading period be worth?  Create an equation to represent any grading period along the way.