A Penny a Day Keeps the Dentist Away

Here's your nightly math! Just 5 quick minutes of number fun for kids and parents at home. Read a cool fun fact, followed by math riddles at different levels so everyone can jump in. Your kids will love you for it.

A Penny a Day Keeps the Dentist Away

November 4, 2015

Coins weigh a lot more than paper money, and aren’t worth as much. So why do we bother carrying them around? Because most things you buy at a store aren’t an exact round number of bills, like a $5 or a $20. And coins are worth something — especially if you save up giant piles of them. As our fans Tiffani and Catherine both shared, a man who’s been saving pennies for 45 years now has thousands of dollars of them! Otha Anders saved a penny one day and decided he’d save every penny he got going forward, whether he found them or just got them as change at the store. He finally brought them to the bank so he could pay his dentist, and they added up to $5,136.14 total! So now Otha has nice clean teeth, and he’s emptied out mountains of pennies from his house. Now he can start saving again, but hopefully he won’t wait 45 years to go to the dentist and use them.

Wee ones: If you have 7 pennies in your pocket and you find 1 more, how many do you have now?

Little kids: If you find a penny starting today (Wednesday), and then every day until the last one on Monday, how many pennies will you have in total?  Bonus: If you save every other penny you find, starting with the 2nd, how many pennies will need to find to keep 6?

Big kids: How many pennies did Otha actually save if they were worth $5,136.14?  Bonus: If Otha had saved 3 pennies a day, would that have been enough to reach $5,136.14? (You can round off to estimate… there are 365 days in a year, but see if you can get it without multiplying big messy numbers.)




Wee ones: 8 pennies.

Little kids: 6 pennies.  Bonus: The 12th penny.

Big kids: 513,614 pennies!  Bonus: It would not have been enough. With 365 days in a year, 3 pennies per day is about 1,000 for the year. So in 45 years he would have about 45,000, nowhere nearly enough. Even 30 per day wouldn’t be enough!

And thank you again Catherine and Tiffani for sending this great math story!

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About the Author

Laura Overdeck

Laura Overdeck

Laura Bilodeau Overdeck is founder and president of Bedtime Math Foundation. Her goal is to make math as playful for kids as it was for her when she was a child. Her mom had Laura baking while still in diapers, and her dad had her using power tools at a very unsafe age, measuring lengths, widths and angles in the process. Armed with this early love of numbers, Laura went on to get a BA in astrophysics from Princeton University, and an MBA from the Wharton School of Business; she continues to star-gaze today. Laura’s other interests include her three lively children, chocolate, extreme vehicles, and Lego Mindstorms.

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