I think MoMath’s weekly puzzle series hasn’t been mentioned on math-fun. In case you want a nice weekly puzzle, consider subscribing (it’s free). They range from numerical, to logical, to somewhat geometric. None require any math beyond algebra, and they each involve some kind of “aha!” insight, explained in the solution sent 6 days later. Last night they had a “Best of Mindbenders” meeting via Zoom. People voted for their most favorite, least favorite, hardest, and most poorly defined puzzle. There have been 23 puzzles so far, and Peter Winkler thinks he has enough more to last until the pandemic is over. The MoMath lady who introduced the meeting said they have 9500 subscribers in many different countries. These puzzles are probably back-of-the-envelope (if not do-in-your-sleep) for math-funsters, but many have generalizations that are non trivial. — Mike

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From: "National Museum of Mathematics" <functions@momath.org <mailto:functions@momath.org>> Subject: Mind-Benders for the Quarantined! Date: March 20, 2020 at 12:03:01 PM EDT To: "Mr. Mike Beeler" <mikebeeler2@gmail.com <mailto:mikebeeler2@gmail.com>> Reply-To: "National Museum of Mathematics" <functions@momath.org <mailto:functions@momath.org>>

Dear MoMath friends, MoMath is pleased to announce a new program to keep your minds fresh! Sign up now for Mind-Benders for the Quarantined! at mindbenders.momath.org <https://momath.org/wp-content/plugins/civicrm/civicrm/extern/url.php?u=2427&qid=24991132> and each Sunday, MoMath will send you a challenging mathematical puzzle from the collection of our own puzzle master, Dr. Peter Winkler. On Tuesday, you'll receive a subtle hint; on Thursday, a serious push; on Saturday, the solution. And the next day, of course, a new puzzle. These puzzles are for your edification, enjoyment, and personal satisfaction. If you wish, however, you may send your answers and/or complaints to mindbenders@momath.org <https://momath.org/wp-content/plugins/civicrm/civicrm/extern/url.php?u=2428&qid=24991132> at any time. Dr. Winkler won't be able to reply, but he will be happy to benefit from your comments, and will announce a winner (for the most right answers with the least help) when the epidemic is over. Regards, National Museum of Mathematics

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