Monthly Math Hour
Math talks given by professional mathematicians from universities across the country, aimed at middle school and high school audiences.
Always free for everyone. No registration required.
The 2026 Math Hour schedule is now available! More details coming soon.
Logistics
Each spring, Seattle-area students in grades 6–10 are invited to participate in the Monthly Math Hour at the University of Washington. We will explore all sorts of interesting mathematics, taught by professors from both UW and across the country. Well-behaved parents, teachers, and siblings are also welcome to attend, with the permission of their children.
The talks are one hour long and will generally occur on Sundays, once a month in the spring, and you are free to pick and choose which talks you want to attend. There will be time for questions and further discussion after the talks.
Registration is not required—just show up! And as always, the talks are free.
Parking at UW is free on Sundays. The closest lot will depend on the building we are using in any particular year, but you can find general information here . Alternatively, the UW campus is generally accessible by Link light rail and King County Metro buses.
Join our mailing list in order to get updates when the 2027 season of Monthly Math Hour begins!
Upcoming Math Hour Talks
Sunday, November 22, 2026: Why Did the Sun Rise on February 29 in 1996 and 2000, but Not in 1900? Pavel Etingof
2026 Special Autumn Math Hour
Join us this November for a special UW Math Hour event by Pavel Etingof. All for free, no registration required.
Speaker: Pavel Etingof , Massachusetts Institute of Technology
Where: JHN 102
When: Sunday, November 22, 2026 @ 1pm–2pm
Why did the sun rise on February 29 in 1996 and 2000, but not in 1900? Why do 22/7 (Archimedes, third century BCE) and 355/113 (Zu Chongzhi, fifth century CE) approximate \(\pi\) so much better than other fractions with similarly sized denominators? Can we build the golden ratio using only 1, addition, and division? These questions lead to continued fractions: fractions inside fractions. We will discover how they lead to Fibonacci numbers, give exceptionally accurate approximations of the golden ratio, pi, and other numbers, and help us design calendars. All you need is curiosity and a little experience with fractions.
Recent Math Hour Talks
Sunday, May 17, 2026: Hidden Cycles, Piotr Pstragowski
Speaker: Piotr Pstragowski, University of Washington
Where: MGH 389
When: Sunday, May 17, 2026 @ 1pm–2pm
What do weekdays, decimals, and error-detecting codes have in common? At first glance, nothing at all. Yet all of them are governed by the same simple idea: keeping track of remainders, which mathematicians refer to as modular arithmetic.
In this talk, we’ll explore how modular arithmetic reveals hidden cycles in numbers, allowing us to quickly predict days of the week, explain the periodic patterns in fractions, and spot mistakes in long strings of digits.
Sunday, April 26, 2026: Taxicab Geometry and Voronoi Diagrams, Maddie Weinstein
This event has passed. Thank you for coming! The slides for the talk can be viewed here:
Speaker: Maddie Weinstein, University of Puget Sound
Where: MGH 389
When: Sunday, April 26, 2026 @ 1pm–2pm
Euclidean geometry assumes that the shortest path between two points is a straight line — but city dwellers know that sometimes buildings get in the way. We will explore taxicab geometry, where travel is restricted to a grid and four is the equivalent of pi, alongside a dog from Euclidland named Pumpkin Pi and his gridlocked companion Pumpkin Four. We will also investigate Voronoi diagrams—ways of dividing space by the shortest distance to given sites— in Euclidean and taxicab geometry and see how this idea was relevant to identifying the source of a cholera outbreak in London in 1854.
Sunday, March 8, 2026: Solving Mathematical Mysteries, Jenny Quinn
This event has passed. Thank you for coming!
Speaker: Jenny Quinn, Seattle Universal Math Museum and UW Tacoma
Where: MGH 389
When: Sunday, March 8, 2026 @ 1pm–2pm
Much as mysteries in fiction consider evidence, find common patterns, and draw logical conclusions to solve crimes, mathematical mysteries are unlocked using the same tools. This talk exposes secrets behind a numerical magic trick, a geometric puzzle, and an unknown quantity to find a fascinating pattern with connections to art, architecture, and nature.
Sunday, October 12, 2025: Rational and Irrational, Andrei Okounkov
This event has passed. Thank you for coming!
2025 Special Autumn Math Hour
Join us this October for a special UW Math Hour event by Fields medalist Andrei Okounkov. All for free, no registration required.
“Rational and Irrational”
What does it mean to be rational or irrational, and why some problems have rational solutions while others don’t?
Speaker: Andrei Okounkov , Columbia University
Where: Mary Gates Hall Room 389, UW Seattle
When: Sunday, October 12, 2025 @ 1pm–2pm
Sunday, May 18, 2025: Applications of symmetry, Monica Vazirani
This event has passed. Thank you for coming!
Speaker: Monica Vazirani, University of California, Davis
Where: Architecture Hall (ARC), Room 147, on the University of Washington-Seattle campus
When: Sunday, May 18, 2025 @ 1pm–2pm
If you want to count the number of tiles in your floor, you probably will not count each one individually, but be lazy and look for a shortcut. For instance, if the room is rectangular and walking part of its perimeter you discover there are 8 tiles along the north wall and 6 tiles along the west wall, you expect 48 tiles total. This shortcut employs the power of symmetry. (And a bit of algebra.)
In this talk, we’ll discuss a powerful counting method that is often referred to as Burnside’s Lemma, although it goes back to Frobenius (1887) and Cauchy (1845). This method uses symmetry and a bit more algebra. We will illustrate the lemma by counting necklaces strung with colored beads. Other applications include counting isomers of a given molecule, crystal structures, chords in a twelve-tone musical scale, Latin squares, and finite automata.
Sunday, April 20, 2025: Corners − edges + faces, Agnes Beaudry
This event has passed. Thank you for coming!
Speaker: Agnes Beaudry, University of Colorado, Boulder
Where: Architecture Hall (ARC), Room 147, on the University of Washington-Seattle campus
When: Sunday, April 20, 2025 @ 1pm–2pm
Choose a Platonic solid among the tetrahedron, the cube, the octahedron, the dodecahedron, and the icosahedron. Start with the number of corners, subtract the number of edges, and add the number faces. Write down the number you get. Repeat this for every Platonic solid. What do you notice? In this talk, we’ll explain what happened and the connection between this curious property of Platonic solids and topology.
Sunday, March 2, 2025: Counting stars, Mark Saul
This event has passed. Thank you for coming! The slides for the talk can be viewed here:
Speaker: Mark Saul, New York University Center for Mathematical Talent/Julia Robinson Math Festival
Where: Architecture Hall (ARC), Room 147, on the University of Washington-Seattle campus
When: Sunday, March 2, 2025 @ 1pm–2pm
How many eleven-pointed stars are there? How often does Christmas fall on a Tuesday? Can a power of two begin with the digit 7? Beginning with an examination of patterns on Native American ceramics, we will look at insights from number theory and analysis into periodic phenomena.
Acknowledgements
The Monthly Math Hour at the University of Washington is supported by the NSF awards DMS-095-3011 and DMS-16000048 and the UW Department of Mathematics.