It’s an awfully short episode of Wrong, But Useful, in which [twit handle = ‘reflectivemaths’] and I discuss:

  • Colin’s upcoming marathon efforts, which you can support by clicking here - bonus points for mathematically interesting sponsorships!
  • Dave’s son Reuben had his appendix removed, and Dave spent the time grumbling (justifiably) about parking and looking for maths, while Colin incorrectly blames nurses for horror stories that could well be the doctors’ fault (oops)
  • We awkwardly congratulate [twit handle = ‘notonlyahatrack’] on becoming a father, and let him off of his homework
  • We talk briefly about [twit handle = ‘primarydeputy’]’s puzzle:

    Arrange the digits 1 to 9 into a nine-digit number such that the first two digits make a number divisible by 2, the first three make a number divisible by 3, and so on.

  • Colin enjoyed the worksheets from mathsbot.com
  • We make zero progress on the envelope problem
  • Colin finally gets to tell the von Neumann anecdote
  • Dave sets this month’s puzzle:

    A regular heptagon has two distinct diagonals, $a$ and $b$. Show that $a+b = ab$.

  • We beg for iTunes reviews
  • Lastly, MathsJam early-bird discount ends on September 30th, tickets going fast