Puzzles To While Away Time

In the event you need something to distract you from the news-of-the-day, a few puzzles from the week…

1)  First some puzzle site suggestions via AMS:

http://blogs.ams.org/blogonmathblogs/2017/06/13/math-puzzles-to-pass-the-time/

2)  Jim Propp begins his own series of video math puzzles here (you know it’ll be good):

https://www.youtube.com/watch?v=epbmEXr1o6s

3)  And from Futility Closet this 1976 prime number puzzle:

https://www.futilitycloset.com/2017/06/14/prime-magic/

4)  And lastly, not exactly a puzzle, but a game using a variation on Tic-Tac-Toe to make it more interesting (or maybe not):

https://mindyourdecisions.com/blog/2017/06/13/who-wins-tic-tac-toe-if-the-second-player-wins-only-for-ties-ft-scamschool-game-theory-tuesdays/