More Math Book

I had a troika of math-for-normals books on the go in parallel at the end of May.  One The Simpsons and Their Mathematical Secrets (2013) by Simon Singh was admittedly more for noodles than for normals. Maths On The Back of an Envelope (2019) by Rob Eastaway is in the tradition of John Allen Paulos [whom bloboprevs] and his A Mathematician Reads the Newspaper (1995). Numeracy is important to prevent yourself or your granny being gulled by nonsense which appears in modern media. Eastaway could, with Simon Singh, Simon Clark, Hannah Fry, Tim Harford, James Grime, Adam Rutherford, Matt Parker, Marcus du Sautoy, Alex Bellos [yes all of blobochecked] make up a cricket team of Explainers of Maths resident in the UK: who therefore know the difference among googol, google and googly.

I twigged that Eastaway was more than {one book picked of a library shelf in rural Ireland} when he wrote about being called up for a crap-detecting soundbyte by local radio. And also about canvassing an audience of teenagers for the weight in stones (rather than kilos which have been curriculum official in UK for the last 50 years). No surprises that he has worked with the UK Math Trust where Gdau.I is currently wrestling kangaroos. Ten years ago he won-a-gong from the IMA [Institute of Mathematics and its Applications] and he's written a dozen books

One of the themes in Envelope is getting numbers correct but not too correct. When RTE reports that 48.34% of people support the bacon-and-cabbage for dinner movement, the number is a blur while "half" or "50%" can be taken in. If  the number is absorbed it may trigger a question like "I wonder what the proportion was in 1996?". It was a time of transition, in 1997 my farming neighbour confessed that his family had frozen pizza for dinner the day before: induced to do so by his teenage daughter. Eastaway suggests using Zequals (a new coinage of his) when trying to get into the right ballpark. Zqualling strips all but the first significant digit. So 7 stays as 7, but 83 ⇒ 80;  83.78 ⇒ 80; 8,452 ⇒ 8000. Pre-process your sums to Zequals and you won't need a calculator but still get a good enough answer: 98 ÷ 5.3 ≈ 100 ÷ 5 = 20.

 Since we got our solar panels, my life is ruined by the kW app on my device. I put off baking until the sun is giving enough to get the oven to 200°C "for free". I put on the immersion when the sun is making 5.25kW [the max] resolving to wash A Lot of dishes or one elderly body before the water gets cold. Towards the end of Envelope, Eastaway offers a poser: which of the following uses the most electricity:

• fridge
• TV on standby
• shower 
• kettle 

Depending on how much tea you drink and how many oxters you possess, shower or kettle (~ 2000W) will win. Leaving fridge ~50W and TV-standby ~2W in the ha'penny place. Apparently, back in the day, TVs would get warm even when nothing was showing, and there was a desultory campaign to make folk unplug them when they went to bed. Not so since we did away with cathode ray tubes and went LED pixels. I knew all that, but Eastaway then riffs on to point out that the family Yaris runs at 20kW or 10x the kettle! "A 30 minute car journey uses more energy than all your domestic appliances put together: that's something to think about when doing the school run". Yes indeed. It reminds me of my dear old dad who would periodically get cost conscious and go though the house flipping off switches while muttering "every light blazing" and "harumph". And then he'd drive into town and buy another lawn-gizmo to clutter his shed.

Nothing in excess [as Delphi sed μηδὲν ἄγαν] is all very well but some excesses are way more excessive than others. Cows burping methane is waaaay more than human pooting the stuff after Beanz Meanz Heinz even accounting for there being 6x more people than cattle on the planet. We shd all give up the ould burgers [two too many poo R]: mutton, chicken, pork are all easier on the planet and lentils least of all.  But cars are an even bigger burden.