Arithmetic that makes you cringe

[mark]

Julio Loace was 24 when, in the summer of 1962... Loace, now 86...

https://www.theguardian.com/world/2022/oct/16/cuban-missile-crisis-60-years-on-russians

Excellent article, even if the writer can't add or subtract very well.

[ian]

I watched a colleague the other day, clever man, scientist, probably has a doctorate, working out percent on a calculator and still needing to do the x100 step at the end.

That's me, that is.

[T42]

A chum of MrsT taking a new first-year science class set them a standard arithmetic test.  One of them got 20/20, a few got 12-14, the rest got less than 10 and a few 0.  Typical question: How many hours in 900 minutes?  That's the kind of question we got fired at us in primary school when I was 9.

I can remember laughing on hearing that first-year physics for medical students in Edinburgh started by defining sin, cos & tan, but that? No wonder she can't wait for the holidays.

[hatler]

First year ?   What age are the students ?

[ian]

I can't really do maths. I got to sit in the corridor because of my thorough disengagement with the process of learning my times-tables. As mentioned, I never learned long division, quite honestly short was taxing enough not to bother with. I mean, if there's an apocalypse that involves all the world's calculators ceasing to work, and the only way to fight off the resulting zombie hoards is through quick fire square roots, I'm screwed.

It's a chance I'm willing to take.

[T42]

First year ?   What age are the students ?

Post-Bac would make them around 18.  The problem for French universities is that anyone who gets their Bac is entitled to a place, and selection takes place at the end of first year once the poor lecturers and tutors are shaking with nerves and popping antacids for their ulcers.

[Giraffe]

review of a watch: "Beating at a frequency of four Hz (28,800 beats per hour)..."

[Slave To The Viking]

review of a watch: "Beating at a frequency of four Hz (28,800 beats per hour)..."

Ooooh, that Hertz.

[mrcharly-YHT]

"Mix .... with 4 gallons (16l) of water"


FFS

[Cudzoziemiec]

Seems accurate enough for round numbers, unless it's specifically UK gallons.

[mark]

4 US gallons = 15.1 liters
4 UK gallons = 18.2 liters
Not really accurate, even for round numbers.

[Giraffe]

What are those quantities in litres?

[Cudzoziemiec]

16 litres is just over 3.5 US gallons and just over 4 UK gallons, so if they can't be bothered to specify which they're referring to and whatever this substance is doesn't need to be mixed particularly accurately (which is hopefully the case, because if it does need to be accurate someone's bound to use the wrong gallons), 4 would be the most appropriate or least inaccurate whole number of gallons to give. Probably.

[JonBuoy]

16 litres is just over 3.5 US gallons and just over 4 UK gallons, so if they can't be bothered to specify which they're referring to and whatever this substance is doesn't need to be mixed particularly accurately (which is hopefully the case, because if it does need to be accurate someone's bound to use the wrong gallons), 4 would be the most appropriate or least inaccurate whole number of gallons to give. Probably.

Erm...is this a special performance for this particular thread?

[Lightning Phil]

16 litres is just over 3.5 US gallons and just over 4 UK gallons, so if they can't be bothered to specify which they're referring to and whatever this substance is doesn't need to be mixed particularly accurately (which is hopefully the case, because if it does need to be accurate someone's bound to use the wrong gallons), 4 would be the most appropriate or least inaccurate whole number of gallons to give. Probably.

You are certainly making us cringe with your arithmetic for UK litres

[Cudzoziemiec]

Bah! Other way round of course. 3.5 UK gallons and 4.2 US gallons. Or 66.6 recurring "legal cups" which sounds like something covered under "Rule 34".

[Giraffe]

Article in the Grauniad about storage of gas under the North Sea:
"A 30km-square reservoir under sandstone, it is twice the size of Lake Windemere."

Windermere is 14.73 sq. km., so rather less than 900 of 'em - or possibly the G has got it wrong yet again.

[Mr Larrington]

The only confusion between x km square and x km² innit.  Words rather than maths.

[ian]

The only confusion between x km square and x km² innit.  Words rather than maths.

This is why scientists can never decorate a room.

[Giraffe]

A 30 km square isn't ambiguous, of course. 30 km squared I do find somewhat ambiguous and much prefer 30 square km - 30 of 1 km*1 km.

[Diver300]

From here:- https://aecramtrucks.com/trx/
which says that a 6.2 litre engine, supercharged to 0.76 bar, turning at over 5000 rpm, uses up to 32.9 litres of air a minute.

The actual figure is either 32.9 m³ or 32.9 kg, I'm not sure which.

[cygnet]

The only confusion between x km square and x km² innit.  Words rather than maths.

This is why scientists can never decorate a room.

I'm sure scientists could order the required amount of paint/wallpaper/flooring. I'm less sure about journalists.

[Tim Hall]

Not arithmetic as such, but I found this on an article about Presta vs Schraeder valves

Your average valve will be between 5-10cm (1.96-3.92″) long

1. Umm, no they're not.
2. Who measures bike valves to the nearest ten thousandths of an inch?  No one, that's who. Over precise conversions. I hate them.

[Kim]

Over precise unit conversions perform the useful function of indicating which unit is more trustworthy.

[Bledlow]

Not arithmetic as such, but I found this on an article about Presta vs Schraeder valves

Your average valve will be between 5-10cm (1.96-3.92″) long

1. Umm, no they're not.
2. Who measures bike valves to the nearest ten thousandths of an inch?  No one, that's who. Over precise conversions. I hate them.

When I visited Sri Lanka I noticed that railway stations had their height above sea level on their name boards.

They were in multiples of 3.05 metres.