Teaching My Kids About Compound Interest (And What I Learned in the Process)

Published on August 12, 2025

Compound interest has been called the eighth wonder of the world, and for good reason. It's a powerful force that can turn a small, consistent investment into a life-changing sum of money over time. It's a concept that I've always understood intellectually, but it wasn't until I tried to teach it to my kids that I truly appreciated its power.

The Marshmallow Test on Steroids

I started with a simple experiment. I offered my kids a choice: they could have one marshmallow now, or if they waited a week, they could have two. It was the classic marshmallow test, but with a twist. The next week, I offered them the same choice: two marshmallows now, or four in a week. I was trying to teach them the power of delayed gratification and exponential growth.

The Surprising Results

My oldest, ever the pragmatist, took the marshmallow every time. My middle child, a natural saver, was happy to wait for the bigger reward. And my youngest, well, she just ate the marshmallow and then tried to negotiate for more. It was a fascinating and hilarious insight into their developing personalities and their relationship with money.

"Compound interest is the eighth wonder of the world. He who understands it, earns it; he who doesn't, pays it." - Albert Einstein

The Lessons I Learned

In the process of trying to teach my kids about compound interest, I learned a few things myself:

  • It's Not Just About the Math: Compound interest is not just a mathematical concept; it's a psychological one. It's about delayed gratification, long-term thinking, and the ability to resist the temptation of the immediate reward.
  • It's Never Too Early to Start: The earlier you start teaching your kids about money, the better. These are lessons that will serve them for the rest of their lives.
  • The Power of a Good Story: The best way to teach a complex concept is through a good story. The marshmallow experiment was a fun and memorable way to illustrate the power of compound interest, and it's a story that my kids will never forget.

Teaching my kids about compound interest was one of the most rewarding experiences of my life. It was a chance to share a powerful financial concept with them, and it was a reminder that the most important lessons in life are often the simplest.