Today we celebrate a Permutation Day! I call days like today permutation days because the digits of the day and the month can be rearranged to form the year.
We can also consider today a Transposition Day, as we need only a single transposition (an exchange of two numbers) to turn the year into the day and date.
Celebrate Permutation Day by mixing things up! Try doing things in a different order today. Just remember, for some operations, order definitely matters!
This unexpected wall art showcasing various forms of hexagons was the reward for walking down a new street. The sprinkler connectors are watching.
Today we celebrate a Permutation Day! I call days like today permutation days because the digits of the day and the month can be rearranged to form the year.
Celebrate Permutation Day by mixing things up! Try doing things in a different order today. Just remember, for some operations, order definitely matters.
My latest column for Quanta Magazine brings the exciting story of superpermutations down to the level of high school counting.
A superpermutation is a string of symbols in which each permutation, or arrangement, of those symbols appears in some order. Imagine, for example, you are trying to thwart the evil plans of a mad scientist and must key in a secret passcode:
Suddenly, inspiration strikes. If you punch in 123451, you’re actually trying two codes: 12345 and 23451. Even better, entering 1234512 will succeed if the code is 12345, 23451 or 34512.
You do some quick calculations. Instead of keying in 600 digits to cover all the possibilities, you now only have to enter 153 digits. You have just enough time — and it works! You’ve saved the day. It’s a good thing you read about “superpermutations” in Quanta.
Finding minimal length superpermutations is a open research problem in mathematics, but recent developments have come from the most unlikely of places! Find our more by reading the article, which is freely available here.
On January 24th I will be participating in a free webinar titled “How to STEM Up Your Classroom” with the NSTA/NCTM National STEM Teacher Ambassadors.
The webinar will feature a number of different perspectives on STEM in the classroom. The teacher ambassadors hail from different states and territories across the country, and work in a variety of settings: high school, K-6, administration, district intervention, policy, and more.
It’s a wonderful group of dedicated teachers with a wealth of expertise to share, and it should be a fun 90 minutes. You can learn more about the free webinar, and register, here.
UPDATE: The full video of the webinar can be found here.
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