*Apologies for a few issues with feedback in this episode. Dave takes full responsibility.*

We discuss:

**Number of the Podcast**: 1089- How to get involved in Maths Week England
- Game Theory (especially isomorphic games) and ncase.me/trust (via @LorHRL Hannah)
- Reading: @benorlin’s Math[s] with Bad Drawings and @robeastaway’s Maths on the Back of an Envelope.
- Via @robeastaway: further thoughts on rounding
- Via @peterrowlett: problem-solving in the new A-level
- Should you tie your shoes on the travelator, or on a standard walkway?
**Shorts**:- Big MathsJam bookings
- Via @octonion (Christopher D Long): "I'm also curious if Haken and Appel's original computer code for the Four Color Theorem from 1972 is still available, and if it can be run on modern hardware. It'd be a sadly missed opportunity for scientific history if it were somehow lost."
- Carnival of mathematics 175
- Election coming up. We want to see your bad graphs!

**Puzzle feedback**: Late solution to the square-colouring puzzle, from Sam Steele, our favourite Antipodean listener in Carrum Downs, Australia. No answers to the pillar problem yet.**New puzzle**: (via @cshearer41) Find the sum of the infinite series $\frac{1}{2} + \frac{1}{4} + \frac{2}{8} + \frac{3}{16} + \frac{5}{32} + \frac{8}{64} + \frac{13}{128} + \dots$ (i.e. Fibonacci on the top and powers of 2 on the bottom).

Next month is the Big MathsJam special!

* Edited 2019-11-08 to fix LaTeX

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]]>**Number of the Podcast**: 179 (balloons)- Maths Week England is mid-November (11-16th). Catherine is involved in running a contest for it!
- Via Peter Rowlett: Women’s names
- Via Adam Atkinson: rounding
*up*or rounding*away from zero*or rounding*to even*? - Reading books: we're all getting our teeth into Rob Eastaway's Maths On The Back Of An Envelope and Kit Yates's Maths Of Life And Death. Cat is also reading Invisible Women by Caroline Criado Perez.
- The Pink Tax
- How much does nursery cost?
- A jury awarded damages of \$8 billion against Johnson and Johnson - as Rob Eastaway says, enough that the victim could budget \$300,000 a day if he lives to be 100.
**Shorts**:- New Chalkdust out now
- Sums of cubes news: they found 3 between recording and going live!
- George Osborn
- Crinkle Crankle walls
- Perfect circle drawing
- Words from obsolete technologies (inspired by clockwise/anticlockwise)

**Puzzle feedback from last time**:- We missed a lovely answer to the probability machine puzzle from @chrishazell72, who worked the ratio out at about 55-45.
- Gold star for Adam Atkinson who said he’d expect 100/e, about 37 squares not to be coloured in. (I think I’ve missed some other stars in my mentions.)

**New Puzzle**(via @davidKButlerUoA): In the middle of my room, there is a pillar. Its cross-section is a square with sides of 1m. I want to draw a circle of radius 2m around the pillar. Obviously I can’t get to the centre to put a compass there - how can I draw my circle accurately?

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]]>**Number of the podcast:**1729, a fairly uninteresting number.- Sums of cubes updates:
- The Collatz conjecture:
- Numberblocks, Sumaze primary, and DragonBox
- GeoGebra
- Number of Core Maths students increased last year
- Pitching core maths?
- Reuben’s homework - Round three dice
**Puzzle feedback**: Gold star for Adam Atkinson who got 4/9 as P1’s win probability. I evaluated a double integral. Silver stars for our favourite listener in Carrom Downs, Australia, Sam Steele and @schwartzstack, who both gave the right answer for the wrong reasons (higher mean doesn’t mean more likely to win).**New Puzzle**: (via @david_cobac You have a 10 by 10 square grid. A number from 1 to 100 is selected and the corresponding square is coloured. This is repeated 100 times. On average, how many squares do you expect to be not coloured in?

The post Wrong, But Useful: Episode 71 appeared first on Flying Colours Maths.

]]>We discuss:

- The Big Internet Math-Off. My favourite pitch wasn’t really in the contest!

I also liked Alex’s wobbly table and Anna’s FURNACE. **Number of the podcast**: 24.- The Winton Centre Quick Quiz for Legal Professionals from @dspiegel.
- Maths Scholarships
- The £50 note.
- The Maryam Mirzakhani Prize in Mathematics.
- The Isaac Newton Institute’s summer puzzles
- Eliasson exhibition at Tate Modern
- What has 4 letters, sometimes 9 letters, but never has 5 letters.
- A claim by Claire’s Accessories.
- Catriona Shearer’s book is available on Amazon: Geometry Puzzles in Felt Pen.
**Puzzle feedback from last time**: The average distance of two points in a unit square. No solutions received! (It’s 0.5214 ish, the result of a tricky double integral.)**New Puzzle**via @ghast_neoh: There are two players, and a machine that outputs a random number between 0.0 and 1.0 when you press a button (inclusive, chosen uniformly and independently, from the reals, etc). Player 1 pushes the button twice, and multiplies the two outputs together to get a score (e.g. 0.45 x 0.9=0.4). Then player 2 pushes the button once, and squares the result to get their score (e.g. 0.67 x 0.67 = 0.4489). The higher score wins. Which player wins more often?

- apparently there are caveats.

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]]>- The Big Internet Math Off and associated stickerbook
- 99 variations on a proof by Philip Ording
- The Art of Statistics - Learning from Data by David Spiegelhalter
- Maths on the back of an envelope - Rob Eastaway
- 1 in 8 men believe they “could” win a point against Serena Williams.
- Green number lines
- via Adam Atkinson: Zachtronics games are now free for school use. Also, "Baba is You" is fun.
- Mathematical objects podcast
- Via @peterrowlett: The Talking maths with your kids hashtag #tmwyk

- That said, I think @draon_dodo has been involved in two previously.

The post Wrong, But Useful: Episode 69 appeared first on Flying Colours Maths.

]]>We discuss…

**Number of the Podcast:**5- Are Fish and Chip shop owners good at maths?
- Two maths puns and a maths joke
- Are there ‘popular’ books that ‘lead you in’ to mechanics?
- An application of the sum-of-squares problem
- Via @PaulsPrattle (Paul O’Malley): “If you were the ruler of the universe tomorrow what would be the objective in secondary mathematics learning for all kids everywhere?”
- Via @aap03102, (Chris Smith)’s newsletter: some love for Simon Plouffe
- Via @christianp: The Big Mathoff is running again
**Puzzle feedback from last time**: We hadn’t seen any solutions when we started recording, but some have come in since - we’ll mention those next month. However: Chris pointed out a tweet from @mathsjem (Jo Morgan) showing the clock-hands puzzle in Thompson’s Practical Algebra, published in 1878.**New Puzzle**: There are 3 lighthouses. The first shines for 3 seconds and then is off for 3 seconds. The second shines for 4 seconds and then is off for 4 seconds. The third shines for 5 seconds and then is off for 5 seconds. Initially, all three come on together. When is the next time they’re all on at the same time?

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]]>- Sheena's
**Number of the Podcast**: 3,212 - Board Games - Number Fluxx, Prime Climb
- Magic: The Gathering is undecidable!
- Oxbridge
- Time surprises
- The oddness of the Fibonacci sequence
- The heights of women
- Big MathsJam Down Under
- Population modelling in the Marvel universe
- The IMU committee for women in mathematics newsletter
- Elwyn Berlekamp has died
- How do you see means?
- The Superpermutation Search
- Via Jeremy Cote: "I've actually seen [J] in a textbook I've used for my real analysis course, but in that case, it was to represent the natural numbers (1,2,3,...). The book is called Introduction to Analysis, and can be found here.
- Other maths podcasts: a list; MathsAt; MakeMathMoments.
**Puzzle feedback:**No stars of any description for the Crystal Maze problem.**New puzzle:**At 3:00, the hour and minute hands on a clock form a right angle. What is the next time that happens?

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]]>We discuss:

- LaTeX (time to fight again)
- Mathematical sign language
- More interesting ‘bad graphs’ than the obvious howlers you usually see on the internet.
- Via @peterrowlett: Some people think statistics has too much significance, and it’s hard to disagree.
- Chalkdust article by @loopspace about Catriona's other, almost-mathematical, hobby, bellringing!
- @mathsobjects, a new podcast from @stecks and @peterrowlett. Any other cases of mathematical discoveries that looked different at the time?
- Does your road have a house 13? 136 votes: yes 56%, no, not long enough 20%, no missed out 24%.
- Escape room advice - don’t use algebra
- (via @ProfSmudge) What’s $\frac{3}{4}$ of $\frac{2}{3}$ - is this surprising or obvious?
- Shapes with different shadows
- Stephen Wootton tweets: @WrongButUseful regarding tax there is also the interesting case between £100k - £120k where the tax free allowance is reclaimed thereby giving rise to an effective tax rate higher than the highest rate of income tax! Keep up the podcasts, thank you.
- via Adam Atkinson: a picture of a 24-hour clock (photo by Daniele Aurelio of Pavia Mathsjam)
- Adam found a book from the 50s or 60s which called the set of integers “J”. “Have you or your loyal listeners ever run into this?”
- @divbyzero asks: Technical math terms the general public uses in a nontechnical way: inflection point (a turning point), squaring the circle (difficult task of reconciling two very different things), in the Venn diagram of _ and _ (in the intersection of), exponential growth (grows fast). Others?
**Puzzle feedback from last time**:**This month’s puzzle**: In a game show, you have four distinct tokens you have to arrange in an unknown order. Every time you guess, you are told1 how many are in the correct position. What strategy gives you the correct answer in the fewest guesses?

- by way of FIRE

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]]>- Chalkdust Issue 091 Fun spring cover with Harris spiral, Horoscope is back!, New academic webpage checklist (c.f. Colin’s old webpage, @standupmaths interview, top ten regulars, etc. Write for them!
- Talkdust, second best podcast: it’s about maths, puzzles, making the magazine, interviews.
**Number of the podcast**: 42. Sums of cubes and open questions- Pi day
- Apologies about audio last time. Dave’s fault.
- Superpermutations and Humble Pi
- Balancing pi on a beam
- One weird trick to deal with percentages
- The Queen Elizabeth Prize for Engineering for 2019 has been awarded to engineers Bradford Parkinson, James Spilker, Hugo Fruehauf and Richard Schwartz for their foundational contributions to the creation of GPS. The prize, worth £1,000,000, celebrates the global impact of engineering on humanity.
- Sumaze Primary, L; Martello Towers; Bloxors
- Dave is wrong about LaTeX

- It’s a magazine for the mathematically curious, apparently. Never heard of it.

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]]>*Apologies for the poor audio quality on this call. Dave's fault, obviously1 .*

We discuss:

- The Talkdust podcast
- (via Adam Atkinson): Life insurance
- Superpermutations: new record for n = 7 in the comments on a YouTube post
- @pecnut and @mscroggs have a LaTeX package that puts hats on things
- Desmos adding support for distributions and all sorts
- @mdawesmdawes’s QUIBANS website
- Dave has been playing the game The Mind
- (Via @peterrowlett), 318,000 combinations of pringles
- Dave gave a talk in Exeter and will hopefully give one in Bristol in June.
- Humble Pi by @standupmaths - book launch on March 2nd in London, tickets
~~selling fast~~sold out. You can join the waiting list here. - @honeypisquared (Lucy)’s new podcast - Mathematips
- We’ve been shouted out in @aap03102 (Chris Smith)’s newsletter, and on @missradders's padlet – thanks!
- Tax - round up or not?
- Rotationally symmetric equations (@robeastaway and @peterrowlett): here, here, and Elliot’s versions here
**Puzzle feedback from last time**: Gold star for @chrishazell72: for showing that $(a-b)^2 + (b-c)^2 + (c-a)^2 + (a+b+c)^2 = 3(a^2 +b^2 + c^2)$, and that the first child is 6, younger (2yo) born when elder was 3.**New Puzzle**(via @cmonMattTHINK): Find the line that touches $y= x^4 - x^3$ at two distinct points. Avoid calculus if possible.

* Edited 2019-02-13 to fix the title. Thanks, Adam.

- Narrator: it was not, in fact, Dave's fault.

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