On this month's episode of Wrong, But Useful, @icecolbeveridge and @reflectivemaths are joined by special guest co-host @christianp. This time, we talk about: Christian, who is involved in @mathsjam and the @aperiodical, and has a number of the podcast: 13. He dislikes it because of its times table; I like it because you can work out thirteenths in your head and look like a ninja, explained in three parts here: Part 1, Part 2, and Part 3. Dave likes 13 because of Belfigore's prime. Colin mistakes 91 for a prime (although immediately corrects himself). He would be lousy at Is […]

This month on Wrong, But Useful, @reflectivemaths and @icecolbeveridge are joined by @evelynjlamb, who is Evelyn Lamb in real life. She writes the Roots Of Unity column for Scientific American. We discuss: How Evelyn got into maths, into writing and into France Evelyn picks the numbers of the podcast: 339,613 and 339,631, both of which are prime. Evelyn recommends @_primes_ (which are prime numbers in real life) We discuss what makes numbers nice and the gods of Tetris and prime numbers. One of Dave’s students has spotted a nice pattern to do with squaring numbers comprising only 3s, only 6s […]

In this episode of Wrong, But Useful: @reflectivemaths and I are joined by special guest co-host Elizabeth A. Williams, who is @realityminus3 in real life (and Zeke, who is Zeke everywhere) Dave picks 367 as number of the episode, as it's the largest number whose square has digits in strictly increasing order (134,689). Colin notes that the first ten digits of the cube root of 2017 are all distinct. Elizabeth brings up @RobJLow's MathsJam talk about balanced ternary Shoutouts to: @christianp on his Mersenne prime birthday – many happy returns @mathjem for writing resourceaholic.com and running… … the Maths World […]

In this month's Christmassy episode of Wrong, But Useful, @reflectivemaths and I discuss: Number of the podcast: 9 Shout outs to: @aap03102 (Chris Smith) for his maths newsletter @mathistopheles (Thomas Oléron Evans) and @fryrsquared (Hannah Fry) for sending me a copy of their book @chalkdustmag for the lovely card @fryrsquared – The Joy of Data on BBC four Mathematics exhibition at the Science Museum “Did you know that the incircle of a 3-4-5 triangle has radius 1?” (Via @arithmaticks): owt to the nowt = 1 Class “Girls were better than boys by 1” (Via @danicquinn): How would you do 12.5 […]

It’s your annual Wrong But Useful Big MathsJam Special! Recorded live, so the audio is a bit shaky in parts. @icecolbeveridge, @reflectivemaths and @peterrowlett discuss Tantrix with some excited background chatter Colin interviews @teakayb (Tom Briggs in real life), who’s at MathsJam with an Enigma machine @pecnut and @mscroggs (Adam and Matthew) tell Colin about @chalkdustmag Dave and Colin review the whole shebang @sparksmaths (Ben Sparks) talks about his musical MathsJam experience A round table with Peter, Dave, @dragon_dodo (Dominika Vasilkova), @mikegibson2010 (Michael Gibson) and an audience of hundreds. Puzzles mentioned: Find three rational squares in arithmetic series with common […]

In the October episode of Wrong, But Useful, @icecolbeveridge and @reflectivemaths have their habitual chat. Dave insults mechanics, then gets stroppy about Colin insulting stats The number of the podcast is 16, 40 and 64, because one number isn’t enough for Dave Dave visits a fete and gets ripped off by a tombola Mathsjam is coming up! Get your tickets soon and prevent Dave from going. Colin plugs his forthcoming book, as per Colin also plugs @colinthemathmo’s appearance on The One Show, juggling Dave buys loads of maths books and a couple of snooker ones; Colin is reading Big Data, […]

In this month’s episode, @reflectivemaths and @icecolbeveridge discuss: Dave is baffled by the idea of the Anniversary Games but happy to have a reduced workload We agree on the name and age of the podcast Number of the podcast: 36, the smallest non-trivial square triangle number. Colin has a new book out August 11th! In multiple languages! And a new one in the works, The Maths Behind…. We discuss ideas for it, invite suggestions, and wonder about brigadiers. Dave is editing a book on Core Maths, a new post-16 course that sounds good. We discuss making maths relevant to young […]

In this month’s Wrong, But Useful, Dave and Colin discuss: Colin gets his plug for Cracking Mathematics in early Colin is upset by a missing apostrophe Dave teases us with the number of the podcast and asks about the kinds of things it’s reasonable to expect students to know, and asserts that the origin of the seven-day week is a quarter of the moon’s cycle. Is that right? So, 28 is the number of the podcast, although the sidereal month is 27.3 days. We point out Big MathsJam conference, which (this year) is the weekend of the 12th-13th of November […]

In this month’s podcast, @reflectivemaths and I discuss: Colin’s book being available to buy Number of the podcast: Catalan’s constant, which is about 0.915 965 (defined as $\frac{1}{1} – \frac{1}{9} + \frac{1}{25} – \frac{1}{49} + … + \frac{1}{(2n+1)^2} – \frac{1}{(2n+3)^2} + …$). Not known whether it’s rational. Used in combinatorics and is $\int_0^\infty \arctan(e^{-t}) \dt $ Chalkdust magazine Issue 3 is out, and the crossnumber is good. Colin and @christianp have cross-checked their answers using Elaborate Codes. Dave attempts to mock Colin for enjoying maths, and is fighting a losing battle. Dave has been reading about Tupper’s Self-Referential Formula, $ […]

In Episode $n$ of Wrong, But Useful (where $n$ is a semiprime followed by two semiprimes and a square), @reflectivemaths and I discuss: Colin’s trip to Center Parcs and whether it is sufficiently central The number of the podcast, which is the tetrahedral angle, $\arccos\left(\frac{1}{3}\right)$ The Other Half podcast Our take on Relatively Prime (Colin wrote up a series of reviews for The Aperiodical) Colin’s guest appearance on Almost Eduational, talking about zero, in which he mentions his forthcoming books, Cracking Mathematics and AS- and A-Level Maths For Dummies Dave’s post expanding on Colin’s Zombie post Dave has bought a […]