Congratulations to all students who participated in QED 2019! You’ll find glamorous photographs in the blogpost following this one, and we hope you are still coveting the ‘fabulous prizes’ you took home Saturday.

#### Silly contests and serious art fairs

We try to keep QED from being too serious. Lawrence Tanzmann runs our annual Guesstimathon, an internet-free challenge with prompts like, “The number of timesÂ *Horse* appears in the songÂ *Old Town Road*” or “The number of pages in the first edition of theÂ *Harry Potter series*” (you can find all the prompts here). The Lowest Positive Integer game asks you to pick the smallest number that no one else does–this year’s winner chose 19 (here’s the distribution of entries). Most popular was our million dollar lottery. You could enter as many times as you like (someone entered 1 billion times), with the unfortunate side effect that the grand prize was $1,000,000Â **divided** by the number of entries. Generously we rounded up the five hundredths of a cent grand prize to a penny.

The highlights, of course, were the QED entries themselves. While some of the project names were also silly (A Can of Worms, Frogs on a Log, Peppermint Experi-MINT), the mathematical content was anything but. Like an Art Fair, there was no competition between entries, just the opportunity to share what you created with the public. Every judge I spoke to after the event was deeply impressed by the level of work they saw.

#### Judges from all over

We’re proud that we draw judges from many walks of mathematical life, from professors to post-docs to graduate and undergraduate students, teachers from primary to middle to high school, along with some combinations of parent-engineer-financial industry wiz-data scientist. Thanks to you all!Â Stu Abram, Maneesha Pradeep, Paul DeRonne, Nailea Curiel, Rutha Dixon, Sam Dodds, Aimee Hart, Jaime McLauglin, Marco Mendez-Duarte, Cornelia Mihailia, Jeremy Judge, Sarah Reitzes, Youjin Lee, Graham Rosby, Minh-Tam Trinh, Matt Rosenberg, Hannah Butler, Melissa Ramirez, Serg Cvetkovic, Abhinav Gandhi, John Marchetta, Faith Medlock, Maxime Bergeron, Kara Fischer, Nate Harman, Edward Huh, Peyton Morgan, Todd Pytel, Kristen Schreck, Eric Xu, and Kevin Zhou.

#### A word of thanks for our sponsors and friends

Peter Tingley went all out as this year’s QED speaker. Dr. Tingley, a professor at Loyola, obtained 600 hackey sacks with QED & Loyola logos to give away (see the photo), for teaching both the mathematics and the practice of juggling. Lawrence Tanzmann ran the Guesstimathon for the nth year running, where I know n to be somewhere between 4 and 7. Steve Starr hosted our Visiting Students who we expect to return in 2020 with new projects!

Julienne Au managed the judges and Mike Caines managed QED’s logistics; that they did so while also managing the logistics of having their newborn onsite was all the more impressive. Lead judges Paul DeRonne, PJ Karafiol, Dan Kang, and Matt Moran made everything run smoothly. Esperanza Baeza, Anabelle Mendez, Grace Shin, Ralph Banasiak, Paul Buckner, and Dzevida Duheric took care of everything else. Go team QED!

The American Mathematical Association again gave every QED participant a recreational math book, and Wolfram gave them each Mathematica, Wolfram Programing Lab, and Wolfram Alpha, the most advanced mathematics software in the world. Chicago’s own Citadel provided food and shirts. Thanks to you all!