A Birthday as Big as a Billboard

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 Birthday as Big as a Billboard

March 15, 2019

We all get Happy Birthday wishes and cards from your friends, family, maybe even your dentist… but what about complete strangers? Well, one man named Chris Ferry is hearing “Happy Birthday” from thousands of people he’s never met! His (grown-up) sons set up the billboard you see here. Since they so helpfully included Chris’ phone number, he’s been getting a text message every minute and about 25 phone calls per hour from well-wishers. And it’s not even Chris’ birthday yet – he turns 62 tomorrow, March 16th. So if you feel like singing Happy Birthday to someone, now you know where to call!

Wee ones: Do you know when your birthday is? What number day is it?

Little kids: The picture of Chris’ head on the billboard is 14 feet tall! If his whole body is 6 feet tall in real life, how much taller is the billboard head? Count up from 6 to 14! Bonus: If Chris stood on the head of another 6-foot-tall person, would the top of his head reach as high as the 14-foot head?

Big kids: If Chris starts getting 2 texts per minute, how many texts will he get in 15 minutes? Bonus: What about in 1 hour? (Reminder if needed: 1 hour has 60 minutes.)

The sky’s the limit: If Chris gets 81 calls on March 17th, 27 calls on March 18th, and 9 calls on March 19th, how many calls do you think he’ll get on March 20th? And what’s the pattern?










Wee ones: Different for everyone! (Though you do share your birthday with lots of other people.) Once you know the number of your birth date, see if you can figure out which number comes next!

Little kids: The billboard head is 8 feet taller than Chris, because you count up 8 steps: 7, 8, 9, 10, 11, 12, 13, 14. Bonus: No, it would not, because 6 + 6 = 12, which is less than 14.

Big kids: 30 texts. Bonus: 120 texts.

The sky’s the limit: He’ll get 3 calls on March 20th, because each day brings 1/3 the calls of the previous day. You might find it easier to work the pattern in “reverse” to see that 9 x 3 = 27 and 27 x 3 = 81, rather than dividing 81 by 27 to find 3.

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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 before she could walk, 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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