The math is to identify all CapEx components, their total life span (assume purchase new), and their replacement cost.  

It's essentially a math problem: what is the best use of your time?  

I seriously need to know how to do the math.

In the last couple months before graduation, I reluctantly signed on with Teach for America as a math teacher (thinking I'd give back to my family's home state, Mississippi).

Let's not get emotional about it, just do the math.

Now that I have assets, rental properties, the same assets they found funny and "not invest-able" at first, they'll beg to work with me, but their fees are crazy....when I do the math, private investing almost seems like it would be a better way to go. 

A financial calculator could do that math, too.Now @Darren Eady says he want's to make 12%.  

In your math you are thinking about doing 20k in repairs with 15k going to a GC.   

My name is Kerri and I am currently a high school math teacher in Ohio.

When I do the math, after all expenses I get about 250$ per month (if the house is rented out).