Welcome Josh.
FV=PV(1+i)n
future value = present value x (1 + interest rate)n
Here is a long explanation in this tutorial HOW TO: Plot Sunrise/Sunset line on a Map and learn how to use equations Do something similar.
Here is a simple example How can I use mathematical formulas?
Use the Math Blocks Math blocks and construct your Blocks. What have you tried? Post your Blocks and someone will provide specific advice.