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**Owing to a spotty connection, the sound quality is a bit patchy on this one. Apologies.**

In this month’s installment, we are joined by Belinda Keir. We discuss:

- Belinda convenes the Sydney MathsJam and is on the committee for the Celebration of Mind
- What makes a mathematician?
- Why Belinda is in a car on a ridge above a scout camp
- How to get non-mathematicians to engage with maths
- Tensegrity structures
- Number of the podcast: 12,288
- When will I ever use that in real life?
- Why @robjlow does maths:

Because it’s fun. Because it’s pretty. Because it fills you with wonder. Because “doing” maths can be different from “using” maths in the same way as reading (or writing) literature is different from filling in a job application form.

— Robert Low (@RobJLow) May 26, 2018

- Colin mentions Cortex Craftworks:

Alright, folks, here we go: Cortex Craftworks is open for business.https://t.co/nhvgEeGieE

I’m selling several kits of the combinatoric tiles I’ve been working on recently — triangles, squares, pentagons, hexagons, and a sampler pack — in several material types. pic.twitter.com/MNrOVdLyfL

— Josh Millard (@joshmillard) June 6, 2018

- Belinda mentions math circles, Julia Robinson Maths Festivals, and Celebration of Mind
- Dave asks: is sudoku maths?
- Colin mentions hyperboloid quilts:

My friend saw this hand-pieced 3D hyperboloid quilt at a quilt show & I am completely losing my mind over this thing. pic.twitter.com/0iZazKzSOk

— satanic vers (@patron_sailor) May 19, 2018

- Art, maths and things growing slowly
- Dave’s campaign to treat maths as art and not useful
- Persistence and solo vs. connected mathematics
- Adam Atkinson found a 24-hour clock in Brescia, Italy. There’s also one at the Piazza San Marco in Venice and one at the Duomo in Florence, which runs counterclockwise and strikes 24 (at the bottom) at sundown/curfew.
- Adam also points to the Italian Superenalotto, in which you pick 6 balls from 90, giving odds of one in 622 million.
- Dave asks: what’s a face and what’s a vertex?
**Puzzle feedback**: No gold stars to give out this time; numbers that reverse when you double and subtract one include 1, 37, 397, 3997. (If you’d like to prove that, it’s a nice enough proof.)**Puzzle**: from Dick Hess via @colinthemathmo. “I have a fish pond. Flat bottom, vertical sides, some water. I have three identical cubes and I want to immerse them to make an underwater platform. First cube goes in, water rises by less than 12 inches. Second cube, water rises by exactly 12 inches. The third, the water again rises by exactly 12 inches. How far under the surface is the platform?”

* Edited 2018-06-13 to correct spelling of superenalotto (thanks to Adam.)