Card Colm

Colm with a crown'

Colm Mulcahy is Professor of Mathematics at Spelman College, Atlanta, GA, where he served as chair of the department 2003-06. He is currently on leave in the DC area, but is always reachable on email.

February/March 2015 lecture tour.

Mathematics Awareness Month 2014 has great resources on "Mathematics, Magic & Mystery" you can use anytime. Math Drives Careers is the theme for 2015!

3 min interview about book, 13 Aug 2013:


          Sci Am         MAA's "Card Colm"           Huffington Post           Aperiodical


Upcoming (see here for available topics):

Nottingham Skeptics in the Pub, The Vat & Fiddle Pub, 7:30pm Thu 26th Feb (booksigning to follow)

Univ of Derby, noon, Fri 27th Feb (booksigning to follow)

Liverpool Maths Soc, Univ of Liverpool, 5:30pm, Mon 2nd Mar (booksigning to follow)

St Rose's Dominican College, Belfast, Tue 3rd Mar

St. Mary’s Grammar School, Magherafelt, 2:40pm, Tue 3rd Mar

UCD's Maths Sparks, Sci H1.49, Dublin, 6pm, Wed 4th Mar

UCD Maths Soc, Ag Sci G08, Dublin, 6pm, Thu 5th Mar

WIT, Waterford, 4:15pm, Wed 11th Mar

Dickinson College, noon, Tue 14th Mar

Smithsonian, Washington, DC, Sat 18 Apr (evening speaker)

AP Calculus Reading, Kansas City, KS, Thu 4 Jun (banquet speaker)

Anja S. Greer Conference, Phillips Exeter Academy, Exeter, NH, Wed 24 Jun



        MAA's Math Horizons (Mathematical Card Magic: Fifty-Two New Effects book review by Rob Eby, Vol 22, No 2, page 28, Nov 2014)

        MAA's Math Horizons ("Thee Cards Suffice" by Colm Mulcahy, Vol 22, No 2, pages 22–25, Nov 2014)

        MAA's Math Horizons ("Undiluted Hocus-Pocus" review and "The Top 10 Things Every Mathematics Student Should Know about Martin Gardner" by Colm Mulcahy, Vol 22, No 1, pages 24–25, Sep 2014)

        "Let the Games Continue" (Sci Am, co-authored with Dana Richards)

        "Math Games of Martin Gardner Still Spur Innovation" (Sci Am)

        "How Well Do You Know Martin Gardner?" (Sci Am)

        "You Don't Have to Be a Genius to Work at Subway..." (Huffington Post)

        NCTM Mathematics Teacher (pages 194-199, with Al Goetz)

        UCD Connections 2014–2015 (page 73)

        Numbers Game

        A Month of Math, Magic and Mystery (Sci Am)

        Google preview of book


        75 second TV clip



36 mins MAA Google Connected Classroom Hangout on Mathematical Magic with Cards, Apr 2014
(re: Mathematics Awareness Month, Day 3)

6 mins video by Chris Morgan of Ice Cream Trick, Oct 2013
(from Celebration of Mind resources)


A Month of Math, Magic and Mystery (Scientific American)
16 Apr 2014

Math’s Best Friend, Martin Gardner (Scientific American)
29 Oct 2013

The Magic of Math (American Univ)
25 Oct 2013

Martin Gardner–The Best Friend Mathematics Ever Had (Huff Post)
20 Oct 2013

All Squared, Number 8 (Aperiodical)
6 Oct 2013

All Squared, Number 7 (Aperiodical)
29 Sep 2013

Inspired by Math (Wild About Math)
21 Sep 2013

Let the Mathemagic Begin (Math Tango)
15 Sep 2013

Spelman’s Own ‘Mathemagician’ (Inside Spelman)
5 Sep 2013


Mathematical Card Magic: Fifty-Two New Effects, foreword by Max Maven
(AK Peters/CRC Press, 380 pages, 128 illustrations, Aug 2013)

cover art of 'Mathematical Card Magic, fifty two new effects'

"Filled with many original ideas that will keep mathematicians and magicians busy for a very long time" — Arthur Benjamin

"A lot of fun. It's clever, instructive, and clear. Learn some tricks. Learn some math. Impress your friends." — John Allen Paulos

"A stimulating collection of novel card magic tricks that .... form a wonderful introduction to important ideas in combinatorics" — Ronald Graham

"A must for your magic library" — Lennart Green


With the late Martin Gardner, in Oklahoma, Mar 2007. The famed writer was a sweet, unassuming and generous man. He played a significant role in enriching the intellectual climate of a nation during the space race era, turning tens of thousands of people on to the joys of creative thinking. In a sense, he did for mathematics what Julia Child did for French cooking. His legacy is celebrated every Oct with Celebration of Mind parties worldwide.


With Ethan Brown, in NYC, Aug 2013, at the first MOVES conference at the groundbreaking Museum of Math. Though he's only starting 9th grade, Ethan is already an energetic blogger, and a protégé of Art Benjamin. He's a total whiz at magic square completion and can do amazing mental arithmetic feats.


With Ron Graham and Persi Diaconis, in San Diego, Jan 2013, at a book signing for their beautiful and inspirational Magical Mathematics: The Mathematical Ideas that Animate Great Magic Tricks (Princeton University Press, 2011) deservedly won the 2013 2013 Euler Book Prize. The wonderful mathematics and magic in that tome is much more sophisticated than that found in Mathematical Card Magic: Fifty-Two New Effects.

(All photos on this and related webpages are copyrighted and may not be used without permission.)
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