Thursday is Pythagorean Triple Day, one of the rarest math holidays.
The numbers of Thursday’s date: 7/24/25 or 24/7/25, fit the pattern of the Pythagorean Theorem: 7 squared + 24 squared = 25 squared.
Any three numbers that fit the a2 + b2 = c2 pattern form a Pythagorean Triple.
Marking time is hard for children (and often for us adults, as well).
I don’t mean telling time, which has its own difficulties. But waiting, marking time until the Big Day or Important Event arrives.
Whether you’re counting down the days to Christmas, or the hours until New Year’s Day, or waiting for a birthday or visit to Grandma — it’s never easy to sit idly during the interim.
Are you looking for fun ways to keep your children busy (and learning!) through the holidays? Here are two printable activity guides you might enjoy…
Would you like your children to play with math during the holidays?
Check out the new printable math activity guide in my online store: Christmas Tree Math Games will keep the whole family playing through the New Year.
Are your students doing anything special for Pi Day?
Back when we were homeschooling, my kids and I always felt stir-crazy after two months with no significant break. We needed a day off — and what better way could we spend it than to play math all afternoon?
I love any excuse to celebrate math!
Pi Day is March 14. If you write dates in the month/date format, then 3/14 at 1:59 is about as close as the calendar can get to 3.14159etc.
(Otherwise, you can celebrate Pi Approximation Day on July 22, or 22/7.)
Unfortunately, most of the activities on teacher blogs and Pinterest focus on the pi/pie wordplay or on memorizing the digits. With a bit of digging, however, I found a few puzzles that let us sink our metaphorical teeth into real mathematical meat.
In math, symmetry is beautiful, and the most completely symmetric object in the (Euclidean) mathematical plane is the circle. No matter how you turn it, expand it, or shrink it, the circle remains essentially the same.
Every circle you can imagine is the exact image of every other circle there is.
This is not true of other shapes. A rectangle may be short or tall. An ellipse may be fat or slim. A triangle may be squat, or stand upright, or lean off at a drunken angle. But circles are all the same, except for magnification. A circle three inches across is a perfect, point-for-point copy of a circle three miles across, or three millimeters.
What makes a circle so special and beautiful? Any child will tell you, what makes a circle is its roundness. Perfectly smooth and plump, but not too fat.
The definition of a circle is “all the points at a certain distance from the center.” Can you see why this definition forces absolute symmetry, with no pointy sides or bumped-out curves?
One way to express that perfect roundness in numbers is to compare it to the distance across. How many times would you have to walk back and forth across the middle of the circle to make the same distance as one trip around?
The ratio is the same for every circle, no matter which direction you walk.
That’s pi!
For all ages:
Sarah Carter created this fun variation on the classic Four 4s puzzle for Pi Day:
Using only the digits 3, 1, 4 once in each calculation, how many numbers can you make?
You can use any math you know: add, subtract, multiply, square roots, factorials, etc. You can concatenate the digits, putting them together to make a two-digit or three-digit number.
For older students:
1. Imagine the Earth as a perfect sphere with a long rope tightly wrapped around the equator. Then increase the length of the rope by 10 feet, and magically lift it off the Earth to float above the equator. Will an ant be able to squeeze under the rope without touching it? What about a cat? A person?
2. If you ride a bicycle over a puddle of water, the wheels will leave wet marks on the road. Obviously, each wheel leaves a periodic pattern. How the two patterns are related? Do they overlap? Does their relative position depend on the length of the puddle? The bicycle? The size of the wheels?
3. Draw a semicircle. Along its diameter draw smaller semicircles (not necessarily the same size) that touch each other. Because there are no spaces in between, the sum of the diameters of the small semicircles must equal the diameter of the large one. What about their perimeter, the sum of their arc lengths?
4. Choose any smallish number N. How can you cut a circular shape into N parts of equal area with lines of equal lengths, using only a straight-edge and compass? Hint: The lines don’t have to be straight.
[Solutions at Alexander Bogomolny’s Pi Page. Scroll down to “Extras.”]
It can be of no practical use to know that Pi is irrational, but if we can know, it surely would be intolerable not to know.
— Edward Titchmarsh
Here are a few pi-related links you may find interesting:
Or for pure silliness:
Have fun playing math with your kids!
Tomorrow is Tuesday 2/22/22 (or 22/2/22, if you prefer). What a wonderfully epic Twosday!
Here’s a puzzle your family or class may enjoy…
Use only the digit 2, and try to use as few of them as you can for each calculation. You may use any math operations you know.
For example:
0 = 2 − 2
8 = 2 + 2 + 2 + 2
You might enjoy practicing your math art skills with this 2-digit challenge from Steve Wyborney.
How many blocks make the digit 2? How did you count them?
Once again, the delightful Nrich Maths website offers a seasonal selection of activities to encourage your children’s (and your own!) mathematical creativity.
Click the images below to visit the corresponding December Math Calendar pages.
Here are twenty-four activities for elementary and middle school, one for each day in December during the run-up to Christmas.
When you get to the Nrich website, click a number to go to that day’s math.
Here are twenty-four favorite activities for middle and high school, one for each day in December in the run-up to Christmas.
2021 Secondary Advent Calendar
When you get to the Nrich website, click a number to go to that day’s math.
I encourage you also to explore my HUGE holiday math post:
Or check out these pages for more ideas:
Have fun playing math with your kids!
My February playful math newsletter went out yesterday morning to all subscribers.
This month’s issue featured a couple of string art projects for Valentine’s Day, the cardioid curve, make-your-own math art, and the link between string art and calculus.
If you didn’t see it, check your Updates or Promotions tab (in Gmail) or your Spam folder. And to make sure you get all the future newsletters, add denise (dot) gaskins (at) tabletopacademypress (dotcom) to your contacts or address book.
Not a subscriber? Don’t miss next month’s playful math activities! Click the link below to sign up today, and we’ll send you our free math and writing booklets, too.
As a Bonus: You’ll receive my 8-week email series “Playful Math for Families” and be one of the first to hear about any new books, revisions, and sales or other promotions
Hiding among all the other winter-themed activity ideas, I found a few posts for those who celebrate the Festival of Lights.
CREDITS: Candle photo (top) by Enrique Macias via Unsplash.com.
I always wait too long to put cards in the mail. Maybe these creative beauties will inspire me to get started right away?
CREDITS: Reindeer photo (top) by Norman Tsui via Unsplash.com.
