MathHappenings are public engagement events designed by the National Museum of Mathematics to celebrate the wonder and beauty of mathematics.

Million Millimeter March for MoMath

MoMath welcomed its one millionth visitor in June 2019!  The Museum marked this auspicious occasion with the Million

Millimeter March for MoMath, beginning at 6:00 pm on 6/6, in honor of reaching visitor number 106.  Hundreds of MoMath enthusiasts received commemorative T-shirts and then embarked upon a one million millimeter walk through the neighborhood, meeting some interesting characters (and some interesting numbers!) along the way.  The last stop was a party in the Museum, where participants celebrated with pizza, dancing, and prizes for the best in geek chic attire.  See more at

Solstice Reflections

December 17, 2018 — In celebration of the season of light, MoMath partnered with the Flatiron Business Improvement District to bring the joyful reflection of a life-sized kaleidoscope to the Flatiron Public Plaza in Madison Square.  In preparation for the shortest day of the year, participants snapped selfies of their own images in multiple reflections.

Previous years:
• Solstice Spirals — December 21, 2017
• Solstice Stars — December 22, 2015 

Solstice Sundial

June 21, 2018 – Together with the Flatiron Business Improvement District, MoMath brought a large-scale human sundial to the Flatiron Public Plaza in Madison Square.  On the longest day of the year, participants traced the passage of the hours with the cast of their own shadows and the help of MoMath’s pavement-top sundial banner.

        Previous years:
        • Solstice Sundial — June 30, 2017
        • Solstice Poly-star — June 20, 2016

Pythagorize Seattle

August 15, 2017 – MoMath returned to Seattle for a second year to celebrate Pythagorus Day 2017 – the last (primitive) Pythagorean triple until 2024!  Made possible by the Bezos Family Foundation, OppenheimerFunds, and Weyerhaeuser, the event unfolded in multiple stages, featuring a city-wide puzzle hunt designed by Lone Shark Games to engage individuals, groups, and families alike. 

        Previous years:
        • Pythagorize Seattle — August 17, 2015
        • Pythagorize the Flatiron — December 5, 2013

Fractal Fun at the World Science Festival

June 4, 2016 — MoMath partnered with the World Science Festival and 144 volunteers to construct a giant glowing fractal!  MoMath’s rainbow-colored lightsticks were used to create a human-scale Koch snowflake in Brooklyn Bridge Park in what became the world’s largest-ever human fractal demonstration.

A Random Walk on Wall Street

May 11, 2016 — Dice rolls, small steps, and a giant group march culminate in a surprising result: a huge human histogram showing the famous “normal curve” of statistics.

Pi Day of the Century

March 14, 2015 — Hundreds of New Yorkers created two giant circles with MoMath’s signature glowing light sticks in order to discover the beautiful recurrence of pi among circles of all sizes. Then, a Pi Countdown clock ticked down the time until 53 seconds past 9:26 pm (that’s Read more at