MSRI: Math Games + Matching Gifts on June 28

Tau Day Puzzle #1
Tau Day Puzzle #1

You may be familiar with Pi Day on March 14th, but there is another mathematical day that is gaining speed: June 28th, also known as Tau Day. Tau Day playfully celebrates τ = 6.28..., which is 2π.

Because the value of tau is twice the value of pi, supporters of Tau Day call for “twice as much pie.” In this spirit, two generous MSRI supporters have offered to match all donations on June 28, 2022, up to $11,000.

For Tau Day 2022, the MSRI invites you to explore a few entertaining yet challenging puzzles centered on Tau, created by Dr. Scott Kominers, whom you may know from Kominers’s Conundrums on You can try Puzzle #1 in the photo, and MSRI will share more on Twitter @mathmoves through June 28!

If you try the puzzle, reply to to submit your answer, or you can try them all on June 28 and submit your answers then to play along!

The first person to submit all four puzzle solutions will receive an official Tau t-shirt (available in black in adult unisex or women's sizes S-4XL) and bragging rights via an MSRI Tau Day medallion.

Tau Fact: Did you know that Persian astronomer and mathematician Jamshīd al-Kāshī computed the value of tau to 16 decimal points in 1424 CE?

Every gift to MSRI 's Tau Day 2022 will be matched up to $11,000 and will support some aspect of the Institute’s mission: Knowledge & Research, K–12 Education, and Public Programs & Initiatives. The generosity of our donor community allows us to fund scientific programming and workshops, outreach projects, and support for individuals including MSRI Postdoctoral Fellows.!/donation/checkout