Jack Frost

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.

Jack Frost

December 28, 2013

You know how windows and mirrors sometimes steam up when you breathe on them, and you can then draw little designs on the fog with your finger? That’s called “condensation,” when lots of tiny drops of water form on cool objects. Sometimes cool grass gets covered with little droplets just like that, which we call “dew” – and if the grass is cold enough to freeze water, those droplets show up as silvery frost. Frost is a layer of thin, tiny crystals shaped almost like the designs snowflakes make, as you can see when frost covers our windows. For hundreds of years people have said that a spirit named Jack Frost is the one spreading this white layer of frost, and also the guy chilling your toes and “nipping at your nose.” He won’t really take a bite out of your nose, thankfully, but when he brings the cold winter air, he might send you hunting for your hat and gloves.

Wee ones: How many letters does the word “frost” have? Count them with a grown-up!

Little kids: If frost can form at 32 degrees and it’s 42 degrees outside, can frost form right now? Bonus: If right now the grass is just 1 degree too warm to get frost, what temperature is the grass?

Big kids: If you live on the northern half of Earth, frost on your north-facing windows will probably melt last in the morning since those won’t get direct sunshine. If your home has 20 windows and 1/4 of them face north, how many frost-friendly windows do you have?  Bonus: If the window’s temperature is 1/4 of the way from the outside temperature to the room’s temperature, and the room is 64 degrees and it’s 20 degrees outside, will the windows be cold enough to frost up? (Assume the windows can be as warm as 32 to frost up.)




Wee ones: 5 letters.

Little kids: No, because 42 degrees is warmer (a higher number) than 32.  Bonus: 33 degrees.

Big kids: 5 windows.  Bonus: The room is 44 degrees warmer than the outside, so the windows are 1/4 of that amount, or 11 degrees, warmer than outside, putting them at 31 degrees. They are cold enough for frost!

And thank you Katarina C. for pointing out the math and science in this great topic!

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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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