I am not sure what you mean by "add 0 to pi" as when you add 0 to anything, nothing changes. When you add anything to pi, in fact, you will never get a rational number. Even if you add an irrational number to pi to try and balance it, pi is infinite and will never be rational when something is added to it.
So what I did was divide $50(Amount at the end) by 6 (the number of months). Which would give me the amount of money he made per month ($8.333...). So then $8.333.../$5000(Total $) is .166...% (Interest rate)
