Ep. 104 – The Superpower Science of Math & Money

Today we’re going to talk about an actual superpower – one that is available to all of us. And it’s a gift from the magical, logical world of math – with a dash of time travel. 

Add math and time to money and we are on the cusp of a semi-boring but powerful formula for financial growth. 

Speaking of boring, that’s how I must sound when I have this money conversation frequently with my Gen Z offspring. Last year, I even took them on a field trip to the Mom Museum (also known as my home office) and I showed them a special exhibit called the check book. 

“You mean you have to write on a piece of paper to give someone money?” said those innocent, digital natives. 

More confusion followed about the ancient need to endorse a paper check vs. just Zelle-ing it to someone. 

Another eye-roll emoji part of Math with Mom often includes me repeating the phrase: “It’s one thing to make money. It’s another thing to keep it.”


Stay with me. There’s more to this story that might even surprise you. 

The Bottom Line on Top of this episode is that one thing better than accumulating money is learning the magical way that money can multiply itself.

So as we dig into how to get money from having money, let’s start with a quick question. 

Would you rather win $1 million dollars or earn $1 million dollars?

Ask this to a lot of people and many may quickly say win it–course!

This isn’t a trick question about taxes (although that’s a real thing), but rather it’s about the insight to income. Winning the money requires nothing but luck. Then you can certainly use skill to make the most of the money that you won. 

But earning the money provides a roadmap to how it was done and how it was built. Hopefully, that map is one that can be replicated or built upon to earn money again. 

I know, I know, it’s less cool. 

Let’s try another idea. In 30 days, would you rather get $1,000 or get a penny that doubles every day for 30 days?

Ah, that’s a bit of a mental trick. And for those of you who are doing some quick math, let me add an extra incentive. What if you could take the $1,000 today and then earn interest on it for the next 30 days. 

Any idea where you would try to put that to get some return? A savings account? Money market? How about the stock market? Or perhaps a little crypto?

Lots of options there. Now let’s go back over to our penny. 

Keeping in my Mom mode, I’ll start this section with a joke: What did one penny say to the other?

Us being together just makes cents

Hey, I’m here to entertain. 

But this is more than humor. This is a point about the power of patience. 

When looking at rates of return on investments, financial experts often start with the Rule of 72. This is a quick formula to estimate how long it will take to double the money invested at a given annual rate of return. 

Rather than make this a complicated example, we’re simply looking at a penny doubling in value every day for 30 days. We don’t need a fancy formula to know that we can double that penny by day 2. And then that doubles the next day to 4 cents, and so on. 

It takes until Day 8 until we break a dollar, $1.64 to be exact and Day 15 actually gets us over $100. Then something interesting starts to happen. 

Remember, the other choice here was to take $1,000 up front – and even included an option to put it somewhere for 30 days to earn some interest. So let’s say you get 5% in a local savings account, you could get an extra $50 on that $1000 if you leave it in that savings account for a year. Mmm that’s pretty good.

But you’ll get more than that by Day 18 with your superstar penny. That’s the point where you will now have $1,800 just from doubling every day. Then on Day 25, you’ll hit six figures at more than $167,000. 

Remember, this doubles every day so by Day 28, you’re a newly minted millionaire. Wait just two more days and now you’re a multimillionaire on Day 30 with $5.3 million dollars. All that from the little penny that could. 

It sounds like a trick, right?

It’s not – it’s the impact of compounding. In this case by doubling every day, and in other areas by earning interest on your interest. 

While some of you pause to go check if what I just said is real, I’ll switch over from money to the investment of effort. We often overestimate what we can do in a day, but far underestimate the cumulative effect of what we can do in a week, a month, and beyond. 

The brain is an easy skeptic and it can initially resist what looks too easy without taking in the larger impact of intentional, incremental growth. Let’s say you have a goal to read more, you could start by reading a page for a day. Quite manageable, in most cases. And then you add a page a day for a month, like we did with our penny.

Like our lucky penny, the growth of the effort seems simple in the early days. And that’s part of the psychology of any slow-growing habit but also slow-growing growth. It’s hard initially to have a really valid excuse for why you can’t do a single effort for a day, whether that’s reading a page,  doing a single push up, writing just one email, throwing away a piece of paper, and so on. 

Once your brain registers the starter effort, it moves the thought from could-do to did-do. This magical dash of momentum then makes the extended effort–the compounded effort of the next day seem a bit more incremental than impossible. 

Small starts, built in tandem, can take our brain further than big bursts of effort with then equally big time lapses in between. 

So as you look ahead to your day today, and even the day tomorrow, think about the power of that little penny and how a small investment you make today could turn into a big result for you in 30 days. 

If the prospect of a month just seems too much right now, try 3 days. Or even 3 hours. It’s not the investment of time here that is the real formula, it’s the belief in the prospect of what you invest in yourself that actually offers the compound returns. 

You can do it – whatever it is. It often takes just as much physical and mental energy to not do something than it does to simply start. 

For today, take a bet on yourself. The promises we keep to ourselves can end up being the best dividend in our confidence and our competence. 

It’s not really about the value of time, in this case, it’s about the worth you assign to yourself. When you choose to take care to take care, go all in. You see, you’re worth it. 

Your brain is hungry. Give it some intellectual snacks in the
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I'm Kristin

I left my corporate work and dove further into how to navigate this noisy, digital, exhausted world. The result is a methodology centered on communications, productivity, and culture that blends theory with practice and helps people better enjoy the life they worked so hard to get.