Math can be extremely frustrating for most of us. Trust me, I understand; I majored in Probability and Statistics and CSU Fullerton. I earned a BA in the subject, and guess what? Math still frustrates me. Thankfully, there are many workarounds that require minimal math effort on my part and produce equal, if not more-precise, results. When ever I have the need to calculate compound interest and/or growth of an investment over time, I can find an application online that performs the required calculations for me - it’s easy!
For example here’s a compound interest calculator that does the job. I only use the applications that don’t require me to sign-up or provide an email address. If signing-up and creating new accounts is okay with you, many investment companies offer their special estimators that can help you invest appropriately. If you are younger, then more aggressively, and if you are older, then more conservatively. These companies can also calculate the total risk of your portfolio so that you can make sure that you are invested appropriately.
So, with all of the free applications and help out there, you do not need to be a mathematical genius to be good with money. Saving and investing is actually more of an art than a science.