Tween Money

Teach Compound Interest through One Grain of Rice

Compound interest: one grain of rice

Last week my son’s third-grade class performed a school play, One Grain of Rice. We had read the book the previous summer as I had heard it was a great book that teaches math. Just check out the Amazon Reviews – have you seen anything so highly rated?

Before I explain the story, I will warn you that this article is going to contain spoilers. If you are a parent reading this hopefully you can live with a spoiled book for elementary-age kids.

The story of One Grain of Rice is simple. A humble peasant does a good deed for the ruling figure and asks for one grain of rice doubled every day for several weeks or a few months. I generalized that because my son’s school play version had some differences from the book version. The good deed, ruler, and time of the grain of rice doubling were different.

The ruler grants the peasant’s request for the doubled grains of rice. Around 20 days he starts to regret the decision as he has to give over a million grains of rice away. Eventually, the peasant becomes the town hero with all the wealth to spread through the town.

Try One Grain of Rice On a Spreadsheet With Your Kids

I found this project with a spreadsheet. I originally found it as a great summary of the story itself, but it’s a great kid-friendly introduction to spreadsheets.

If you get used to using the spreadsheet it will be useful when you try to model one grain of rice with money:

One Grain of Rice With Money

Taking the lesson of One Grain of Rice and applying it to money isn’t a stretch. In the story, rice is essentially the kingdom’s form of currency. (It makes more sense than using bees as currency)

It would be nice if we could double our money every day, but there’s not an investment in the world that would do that. Instead, you may choose to explain that it’s reasonably possible to double your money every 6 years or so. Some parents out there might be familiar with the Rule of 72. The Rule of 72 states that money doubles every X years depending on the growth percentage. For example, if you are earning 5% interest, it will take about 14 years for your money to double – (72 divided by 5 is about 14 years). If you can earn 12% interest, it will only take 6 years for your money to double – (72 divided by 12 is about 6 years).

Assuming a 12% interest rate over the long haul may stretch reality a bit. The stock market has returned that much for long periods, but it’s far from a guarantee. It’s more of an exception than the norm. We’re looking to motivate kids with the power of investing, so you may want to focus on the sunnier side. You also may want to create your own Bank of Dad where you can afford to pay higher guaranteed interest rates (at least for a little while).

You may want to run a few scenarios with your kids. Using that “money doubles every six years” you could find that you have 5 or 6 doubling events by the time they are mom and dad’s age. By that time, a dollar invested at their age might be $32. One hundred dollars would be $3,200. You can blow their minds by going to 10 doubling events in 60 years when a dollar is worth over $1000. Of course, they might not care because it’s hard for kids to imagine a 68-year-old version of themselves.

Grandpa’s Fortune Fables (Book Review)

Grandpa's Fortune Fables

On my Kid Wealth Twitter account (@KidWealth), I noticed a lot of my followers saying how good Grandpa’s Fortune Fables by Will Rainey is. I started following him and his Blue Tree Savings website. He had some great blog posts about a millionaire janitor and how McDonalds really makes their money.

Naturally, I fast-tracked Grandpa’s Fables to the top of my “to read / to review” list. To be honest, it helped that the Kindle price is currently $3. This was an easy buy because I get to help a fellow kid financial literacy advocate… and because I could be frugal at the same time.

Grandpa Fortune Fables’ Audience

Grandpa’s Fortune Fables was written for kids ages 7-13. This is a much better fit for my kids (age 8 and 9) than M is for Money. That book was aimed at younger kids. I was able to read it myself over two days. I’m a slow reader and it took me around a couple of hours. It’s 21,339 words (that information is a tiny bit of a spoiler that you get at the end of the book).

My 8-year-old is at a guided reading level of “N” and he did two chapters earlier today. I was hoping to have my kids read it and contribute to this review, but they could sense that it was “learning” and resisted. When I convinced my 8-year-old to read one chapter, he read a second one on his own because he wanted to solve the money code. Each chapter has a question at the end about the main idea. The correct answer corresponds to a letter. Get all the letters and you solve the money code, which can be used for a discount to a money club.

Maybe it’s my kids, but I’ve found that a book needs to have a gimmick to hook my kids. They’re busy with school, karate, soccer, baseball, scouts, music lessons, Duolingo, etc. I can understand why they wouldn’t want to do extra reading.

Grandpa Fortune Fables’ Format

I had expected the book to have different, unrelated money fables. I was pleasantly surprised to find that all the fables are connected by a running story of a couple of main characters. Most of the chapters end with a bit of a cliffhanger, which made it difficult to put down. I wasn’t expecting to read it in two days, but I just kept on flipping through to the next chapter to see what the next money lesson would be.

The characters themselves are a little reminiscent of Rich Dad, Poor Dad with one character who is good with money teaching the kid who comes from a family with poor money management. Rainey does list Rich Dad, Poor Dad as one of the inspirations for his book. It’s a little outside the scope of this review, but I’ve included more information at the end of this article about why I cringed when I saw this. Fortunately, readers of Grandpa Fortune Fables can be blissfully unaware of this reality and still get great financial information.

Grandpa Fortune Fables’ Money Lessons

There are 14 money lessons covered in the book. They are:

  1. Everyone Can Become Wealthy
  2. Getting Rich Quick
  3. Rich Vs. Wealthy
  4. Working Smart
  5. Kid Entrepreneur
  6. Save Then Spend
  7. Invest
  8. Debt and Gambling
  9. Tax
  10. Risk
  11. Strategy (Leave Investments Alone)
  12. Home is not an Asset
  13. Charity
  14. Starting a Business

Almost all of the chapters are done extremely well – so well, I couldn’t imagine any way to improve on them. However, the chapter on debt used a metaphor of growing red trees to illustrate debt seemed out of place. I understood what the metaphor meant knowing that compound interest in the form of debt can work against you. It just wasn’t clear in the book why the character loaning the money would plant a tree to represent how much debt the borrower would need to pay back. Even then, I can’t think of a better analogy to model it.

The chapter on your home not being an asset is a valuable lesson, but I’m not sure how relatable it is for the average 10-year-old who doesn’t own a home. This is one money lesson that will probably need reinforcement every few years until the young adult gets to house-buying age. This chapter will be a great discussion with our kids when they ask about why all their friends live in mansions and we live in a more modest house.

Final Thoughts on Grandpa Fortune Fables

I may have been overly critical on a couple of minor points of this book. I think that’s because it is overall so well done that those minor things stood out to me. I have previously said that If You Made a Million is the best personal finance book for kids, but Grandpa Fortune Fables surpasses it. In hindsight, If You Made a Million, tries to cover too much taking you from a description of what a penny is to financial independence by earning interest on a big nest egg.

The stories in Grandpa’s Fortune Fables are more engaging than the If You Made Million. I would love to have seen this book come home from school because my kids would have had less resistance to reading it. It should be the core book of any financial education for kids ages 7 to 13.

The problem with the Rich Dad, Poor Dad

Rich Dad, Poor Dad is widely considered the worst personal finance book. It comes up on most search results for “Worst Personal Finance book.” The author Kiyosaki himself seems to be modeled in Grandpa’s Fortune Fables as Shovel Sam – the scammer who tells everyone that there is gold on the island so he can get rich selling shovels. Kiyosaki is active in the MLM/pyramid scheme community. He’s also sold a $45,000 course on real estate and suggested that people fund it with credit cards.

You can learn more about these courses in this CBC Marketplace news expose:



Nonetheless, Robert Kiyosaki filed for bankruptcy. There’s so much negative with Kiyosaki it’s hard to know where the bad money lessons end.

Teach Your Tween About Money

Teach Your Tween About Money

The tween years (10-13) is the most exciting time to teach a kid about money. It is perfect for four reasons:

  1. Tweens have enough math skills to handle some difficult concepts.
  2. Tweens are old enough to want more expensive things. This means they’ll need to save money.
  3. Tweens are old enough to make money on their own through side hustles.
  4. Tweens still look up to you and don’t have the freedom to ditch you for their friends just yet. In other words, you can still influence them.

Tween math and money skills

tween moneyWhen I was a kid, the concept of compound interest got me hooked on personal finance. Back then banks were paying interest rates between 6-8%. The act of saving money was the same as investing it. Banks aren’t paying that kind of interest nowadays, but you can open up your own bank and subsidize those great interest rates.

When I introduced my 8-year-old to MoneyTime Kids it was a little cruel. It’s designed for tweens between the ages of 10-14. While he could understand many of the concepts the math was difficult and he wasn’t able to take full advantage of it. He’s nine and a half now and I think that 18 months has made a big difference. He went from only knowing half of his multiplication tables to multiplying 3 digit numbers and long division.

Tweens want more expensive things

There are still some times that my 8 and 9-year old boys are fine with a cheap knick-knack. However, more and more they are becoming more interested in expensive things. It started with the Switch and now it is games for the Switch. Fortunately, the Pokemon games they like tend to have a lot of replay value.

Soon my kids will be hanging out with friends more and spending money with them. I’m sure they’ll want to fit in with the latest shoes and clothes. While we’ll always get them certain shoes, if they want the best designer brands, they’ll have to cover some of the cost. That’s an opportunity for them to learn about saving and budgeting.

Tweens and side hustles

Tweens aren’t old enough to work “in the real world.” I had to wait until I was 16 before I could work at a fast-food restaurant. I saw that Mcdonald’s was advertising for kids age 14 to work there.

Fortunately, tweens can do some side hustles. Babysitting and mowing lawns is perfect for many 12 and 13-year-olds. This is a good way for them to earn significant money.

Tweens will still listen to parents – some times.

I know that when my kids are teens they’ll have better things to do than listen to me give them money lessons. They may not agree with me, but at least there’s a chance that they pay some attention.

Final thoughts about tweens and money

There are so many different directions you can go to teach your tween about money. Beyond what I already included in the article, this is a great age to give them insight into the family finances.

American Girl: A Smart Girl’s Guide to Money (Book Review)

American Girl: A Smart Girl's Guide to Money

American Girl is a strange brand to put out a guide to money. Some of their dolls cost hundreds of dollars. That’s before you get into the extra clothes and accessories. My wife sold five of her niece’s American Girl dolls for around $500. They were used, without the boxes, and in some cases not even in the original clothes. Back when the nieces were in their American Girl phase my wife saw the prices on the accessories in a catalog and quipped, “I hope you get an American job that pays American money for this stuff.”

I have to admit that when we found out that we having were boys, a part of me was relieved to not have to get drawn into that consumerism. Instead of American Girl stuff, my kids got drawn into Pokemon consumerism. I don’t know if that’s any better.

When my wife saw the book, American Girl: A Smart Girl’s Guide to Money by Nancy Holyoke, we joked that it must be one page long with only four words, “Don’t buy our products!” However, it was used and only a couple of dollars. Curiosity got the best of me, so I bought it. The copy I have is the original version from 2006 and that link is to the revised version that’s in print today. It has a different illustrator, but the same author. Using Amazon’s “Look Inside” feature, it seems like the content itself is the same and the illustrations are just as good – it’s just a different style.

So, with two boys and no daughters, I’m going to attempt to review a personal finance book for teenage girls by a company that sells outlandishly priced products. None of this makes any sense, but this is where we are.

To start, the book isn’t one page and four words long. It’s 95 pages, with colorful illustrations on every page. It’s the perfect presentation for a teenage audience. I can’t emphasize that enough, because getting kids to choose to read about personal finance is not easy. A teenager will plow through this book quickly. I’m tempted to ask my 9-year-old son to read it, but I know it would have be a big bribe – teenage girl books are weird for 9-year-old boys. I’ll give it a try anyway – chocolate usually works. Also, it would give me a chance to put a few dollars in his how to teach kids about money. Finally, there is a page about the power of compound interest.

The book closes out with a few pages on donating to charity. It also included one page about how $20 can mean different things to different people and even different things to you based on how you acquired it and what the expectations were. This particularly resonated with me. I can spend hours writing an article for this site. A dollar earned here means much more than a dollar earned in salary.

American Girl: A Smart Girl’s Guide to Money isn’t a complete guide. For its intended audience, it is close to perfect. It teaches just enough without getting too long and complicated that teenage girls would simply not read it.

MoneyTime Review: Teach Your Kids Personal Finance

Money Time
MoneyTime – Personal Finance for Kids

I have two boys, one in the second grade and one in the first grade. My second grader is doing basic math with money at school, things like making change correctly. It’s certainly a good start, it is math disguised as adding and subtracting tens and twenty-fives. My kids learn more about personal finance when I take them shopping and show them how I compare unit pricing on a jar of spaghetti sauce. For the most part, I should be focusing on how to give your child an allowance.

Alas, two of my greatest interests in life are personal finance and my kids… I would inevitably try to combine the two. I can’t teach all personal finance through television. So when I heard that MoneyTime was an online class for teaching kids personal finance, I did a little research and reached out to them to find out more. Every week, I get a dozen or more companies asking me to pitch their product or service. This was one of the few times that I’ve reached out to the company. (You may have noticed that I review very few services.)

MoneyTime Review: The Overview

MoneyTime is designed for kids between the ages of 10 to 14. From their FAQ:

“We’ve found after testing that children below 10 years old found the math to be a little too complex and those above 14 found the graphics of the game to be too childish. That’s why this age range is perfect for MoneyTime.”

My 8-year-old is in challenge math classes at school, so I figure it was worth a shot. All year, he’s been getting extra instruction in school about how to work with computers just in case they have to go to home-schooling. That proved very helpful in getting him going with the basics of navigating the application. They were right about the math though. Early on, there were some multiplication questions. Armed with his Multiplication Machine, he was ready to go. I was always nearby, but he only called on me a couple of times. If I wasn’t a personal finance blogger (and a Tiger Dad) curious to push the age limits, I would wait until age 10 for the kid to get the most out of the classes.

Money Time Screen

The MoneyTime system is broken up into 8 major topics:

  • Topic 1: Earning, saving and interest
  • Topic 2: Employment
  • Topic 3: Managing your money
  • Topic 4: Borrowing money
  • Topic 5: Property
  • Topic 6: Investing
  • Topic 7: Business
  • Topic 8: Protecting your money

Each of those topics is broken up into 4-6 modules or lessons. For example, “Managing your money” has modules of Smart Spending, Budgeting, Banking, and Paying. I’m not sure that a 10-year-old needs to consider employment in topic 2, especially the “resume” module. However, I think it’s based on the outline of “earn, save, invest” in that order.

My son completed the first topic, so this review will be based only on that section. The lower right-hand part of the dashboard gives you a little view on how that went:

MoneyTime Dashboard

If you read from the bottom up, you can see my son got only 67% of the pre-test questions on earning, saving, and investing correct. I was very impressed by this pre-test because had little exposure to some of the topics. I had to remind him a couple of times that he wasn’t expected to know the answers. I used this opportunity to teach him how to eliminate some answers that seemed obviously wrong and then take his best guess of what’s left.

After a module of instruction, there is a 10 question quiz. He got 60%, 90%, and 80% respectively on the earn, save, invest sections. The invest section introduced the difference of compound interest vs. simple interest – a distinction he still talks about today. When it came to the final review test on the topic of saving, earning, investing, he scored a 93%. I expected some improvement because he was learning the material on the test, but this was outstanding.

MoneyTime Keeps Kids Motivated

You may have noticed that my son has an avatar of a weird orange bird superhero. He likes fire-type Pokemon and my theory is that this most closely resembled Blaziken – the fire chicken.

You can spend your earnings (which come from completing modules) on improving your avatar. This was an important motivation for my 8-year-old. He also made investments in education (the stack of books) and investments (the treasure chest). The education helps him earn more as he completes more modules, he’ll earn more. This seems to be a little like the game of life where having a good career helps you earn more from the “Pay Day” spots on the board. His current job as a “trainer” earns $1000 a year. His $5,500 savings is enough to upgrade to Carpenter that would give him a 50% raise per year ($1500).

It’s not clear to me how years pass in this world, but I think it’s because we stopped where we did. My son did one topic (the three modules) over two days during school break. He hasn’t gone back to it since then. I don’t think it is because MoneyTime didn’t have the staying power. Instead, my kids simply don’t have a lot of time with school/homework/karate/cub scouts/etc. I want them to have some unstructured time as well. We should revisit it over the summer. He’ll have more free time and be almost 9 then.

MoneyTime Review: The Conclusion

I gave you our experience with MoneyTime, but I think the company’s professionally-made, less than 90-second, video shows off a little more from a different perspective. It’s worth the quick watch:

There are a couple of online courses for kids and personal finance, but this is the first one I’ve tried. It works very well. Then again, kids’ personal finance education is non-existent, so the bar is very, very low. When I think of what we spend on karate/skiing classes and specialty camps, the value of this education is way, way, off the charts.

This link will give you 25% off bringing your annual membership to $49. That price is current as of this writing (1/26/2022). They have a deal going on now. The pricing used to be $99 a year. If you think it’s something that you might be interested in, I would buy it now. In the interest of full disclosure, I should mention that the company will give me a commission on sales.