Author Topic: Arithmetic that makes you cringe  (Read 78081 times)

Re: Arithmetic that makes you cringe
« Reply #100 on: 30 September, 2019, 11:52:54 am »
Yeah, I think what they're trying to suggest (though the unclear photo does little to corroborate this) is that the space is (2m)x(2m) or (6'7")x(6'7").
You're absolutely right that 2m2 is 22 sq ft.

Phil W

Re: Arithmetic that makes you cringe
« Reply #101 on: 30 September, 2019, 12:32:36 pm »
Quote
The fact that they've tried to show the equivalence makes me think it was (2 metres) squared, which is 4 square metres, or 43 square feet.
That in itself leads to misunderstandings.  it is not 2 metres squared but 2 metres square which means it is a square with 2 metre sides.  I noticed this modern use of squared in one of those fly on the wall school programmes.   In the answer to a question, little Johnny replied "2 metres squared" when the correct answer would have been "2 square metres".  Little Johnny thought the 2 always meant squared.  Of course the teacher did not correct him.  Lets hope he never becomes a carpet fitter.

The teacher may well become a carpet fitter.

T42

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Re: Arithmetic that makes you cringe
« Reply #102 on: 30 September, 2019, 01:00:04 pm »
Quote
The fact that they've tried to show the equivalence makes me think it was (2 metres) squared, which is 4 square metres, or 43 square feet.
That in itself leads to misunderstandings.  it is not 2 metres squared but 2 metres square which means it is a square with 2 metre sides.  I noticed this modern use of squared in one of those fly on the wall school programmes.   In the answer to a question, little Johnny replied "2 metres squared" when the correct answer would have been "2 square metres".  Little Johnny thought the 2 always meant squared.  Of course the teacher did not correct him.  Lets hope he never becomes a carpet fitter.

The confusion probably comes from reading 2 m² as if m is a variable - we say a² as "a squared" rather than "square a's".
I've dusted off all those old bottles and set them up straight

Kim

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Re: Arithmetic that makes you cringe
« Reply #103 on: 30 September, 2019, 01:46:05 pm »
The confusion probably comes from reading 2 m² as if m is a variable - we say a² as "a squared" rather than "square a's".

I don't actually think that's confusing, unless you read it out:  BODMAS[1] requires that you square the metre (to get square metres), then multiply by 2.

Doing maths on the units is normal and ordinary in physics, so there's nothing particularly special about length and area.  Unless your maths education stops at carpet-fitting 101, I suppose.


[1] Other mnemonics are available.

T42

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Re: Arithmetic that makes you cringe
« Reply #104 on: 30 September, 2019, 03:30:36 pm »
It's a reasonable mistake for a child to make, though. Not so forgivable for an adult, even if they do work for the Beeb - although I believe there are people who go into denial of maths once they leave school.

Reminds me for some reason of a candidate I once interviewed for a place as programming intern: I asked her what programming languages she had studied so far and she replied "I don't know, I wasn't paying attention".
I've dusted off all those old bottles and set them up straight

Kim

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Re: Arithmetic that makes you cringe
« Reply #105 on: 30 September, 2019, 04:02:27 pm »
Reminds me for some reason of a candidate I once interviewed for a place as programming intern: I asked her what programming languages she had studied so far and she replied "I don't know, I wasn't paying attention".

I think I remember offering to help her with some Java coursework.  When asked what it was she didn't understand, the answer was "Well, Java".

essexian

Re: Arithmetic that makes you cringe
« Reply #106 on: 30 September, 2019, 04:40:48 pm »
Did anyone see: "Who wants to be a millionaire" a couple of weeks back? One of the questions was something like: What answer do you get if you add 9+8+7+6+5+4+3+2+1?  The answers given were something like: 40, 42, 45 or 48.

Yes, they (a teacher if I remember) got it wrong.  :facepalm:

caerau

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Re: Arithmetic that makes you cringe
« Reply #107 on: 30 September, 2019, 05:20:08 pm »
Did anyone see: "Who wants to be a millionaire" a couple of weeks back? One of the questions was something like: What answer do you get if you add 9+8+7+6+5+4+3+2+1?  The answers given were something like: 40, 42, 45 or 48.

Yes, they (a teacher if I remember) got it wrong.  :facepalm:


Yes that was cringeworthy - to a point - she could have taken more time - but under that pressure in front of the cameras... easily done.  There but the grace of bod...
It's a reverse Elvis thing.

ian

Re: Arithmetic that makes you cringe
« Reply #108 on: 30 September, 2019, 06:09:22 pm »
Quote
The fact that they've tried to show the equivalence makes me think it was (2 metres) squared, which is 4 square metres, or 43 square feet.
That in itself leads to misunderstandings.  it is not 2 metres squared but 2 metres square which means it is a square with 2 metre sides.  I noticed this modern use of squared in one of those fly on the wall school programmes.   In the answer to a question, little Johnny replied "2 metres squared" when the correct answer would have been "2 square metres".  Little Johnny thought the 2 always meant squared.  Of course the teacher did not correct him.  Lets hope he never becomes a carpet fitter.

To be fair, as a scientist, I was puzzled to find that umpteen square metres of promised paint cover did not turn out to be as anticipated.

Cudzoziemiec

  • Ride adventurously and stop for a brew.
Re: Arithmetic that makes you cringe
« Reply #109 on: 01 October, 2019, 10:09:47 am »
The public toilets have been closed for a couple of years. If you can't have a pee, have a pi!
https://www.bristol247.com/news-and-features/news/mathematical-graffiti-in-the-bearpit/
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Kim

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Re: Arithmetic that makes you cringe
« Reply #110 on: 01 October, 2019, 12:03:08 pm »
Quote
The fact that they've tried to show the equivalence makes me think it was (2 metres) squared, which is 4 square metres, or 43 square feet.
That in itself leads to misunderstandings.  it is not 2 metres squared but 2 metres square which means it is a square with 2 metre sides.  I noticed this modern use of squared in one of those fly on the wall school programmes.   In the answer to a question, little Johnny replied "2 metres squared" when the correct answer would have been "2 square metres".  Little Johnny thought the 2 always meant squared.  Of course the teacher did not correct him.  Lets hope he never becomes a carpet fitter.

To be fair, as a scientist, I was puzzled to find that umpteen square metres of promised paint cover did not turn out to be as anticipated.

To be fair, paint-manufacturer square metres are a bit like tent-manufacturer persons.

Re: Arithmetic that makes you cringe
« Reply #111 on: 01 October, 2019, 12:09:38 pm »
To be fair, paint-manufacturer square metres are a bit like tent-manufacturer persons.

Since a tent manufacturers designated four man tent is usually only suitable for three people, a three for two and a two for one I often wonder who their one man tents are designed for ....
I think you'll find it's a bit more complicated than that.

arabella

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Re: Arithmetic that makes you cringe
« Reply #112 on: 01 October, 2019, 07:40:49 pm »
For me!
and other persons of sensible size.

If only I could find the corresponding sleeping bag rather than one made for a 6' plus user.
Any fool can admire a mountain.  It takes real discernment to appreciate the fens.

Kim

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Re: Arithmetic that makes you cringe
« Reply #113 on: 01 October, 2019, 07:48:00 pm »
When SmallestCub was a bit smaller than he is now[1], we decided that we could both fit in my Akto.


[1] Though not small enough to use that Jiffy bag as a sleeping bag any more.

Cudzoziemiec

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Re: Arithmetic that makes you cringe
« Reply #114 on: 01 October, 2019, 07:57:01 pm »
I'd have said it was a bit different. A 1-person tent is the right size for 1.2 persons, a 2-person for 1.8, a 3-person for 2.6 and similar.
Riding a concrete path through the nebulous and chaotic future.

Re: Arithmetic that makes you cringe
« Reply #115 on: 02 October, 2019, 08:47:58 am »
Quote
The fact that they've tried to show the equivalence makes me think it was (2 metres) squared, which is 4 square metres, or 43 square feet.
That in itself leads to misunderstandings.  it is not 2 metres squared but 2 metres square which means it is a square with 2 metre sides.  I noticed this modern use of squared in one of those fly on the wall school programmes.   In the answer to a question, little Johnny replied "2 metres squared" when the correct answer would have been "2 square metres".  Little Johnny thought the 2 always meant squared.  Of course the teacher did not correct him.  Lets hope he never becomes a carpet fitter.

It's quite likely that the teacher doesn't know the difference either. As Kim says, it's becomes an issue when read out loud. However, it also becomes an issue when people start to think that 2m2 is the same as (2m)2. A few years ago I was invited to presentations from Masters level students on Environmental Impact Assessment (EIA) projects. My general feedback at the end of the session was that at least 3/4 of the presentations were using the phrase xxx metres squared, when they meant xxx square metres. Using it as a mental shorthand is one thing, but telling the regulator that there will be loss of an important habitat of 100 square metres when you meant 10 square metres because you've said "10 metres, squared" could be the difference between the project being permissible or not.

Cudzoziemiec

  • Ride adventurously and stop for a brew.
Re: Arithmetic that makes you cringe
« Reply #116 on: 02 October, 2019, 09:14:01 am »
I've always thought of 2m2 as 2 square metres and a space 2m x 2m as a 2-metre square. Perhaps it would be clearer if we used a distinct term for area, so 2m2 would be 2 centiares.
Riding a concrete path through the nebulous and chaotic future.

T42

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Re: Arithmetic that makes you cringe
« Reply #117 on: 02 October, 2019, 09:15:29 am »
Small wonder that the newspapers talk in football pitches, esp when the Gardyloo uses a US reporter and replaces field by pitch but doesn't change the figure.

Disclaimer: I haven't the foggiest idea how big a football pitch (or field) is. Several thousand square elephants, I should think.
I've dusted off all those old bottles and set them up straight

T42

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Re: Arithmetic that makes you cringe
« Reply #118 on: 02 October, 2019, 09:17:27 am »
I've always thought of 2m2 as 2 square metres and a space 2m x 2m as a 2-metre square. Perhaps it would be clearer if we used a distinct term for area, so 2m2 would be 2 centiares.

Centiares?  Not even in France, where people already talk in ares, have I heard that term.

Any relation of Nessus?
I've dusted off all those old bottles and set them up straight

Cudzoziemiec

  • Ride adventurously and stop for a brew.
Re: Arithmetic that makes you cringe
« Reply #119 on: 02 October, 2019, 09:17:38 am »
Confused by hectares? You will be after reading this!
https://www.linkedin.com/pulse/understanding-land-sizes-measurement-ann-nwaukwa
Riding a concrete path through the nebulous and chaotic future.

T42

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Re: Arithmetic that makes you cringe
« Reply #120 on: 02 October, 2019, 09:19:08 am »
Don't think I'll bother.
I've dusted off all those old bottles and set them up straight

Cudzoziemiec

  • Ride adventurously and stop for a brew.
Re: Arithmetic that makes you cringe
« Reply #121 on: 02 October, 2019, 09:19:22 am »
I've always thought of 2m2 as 2 square metres and a space 2m x 2m as a 2-metre square. Perhaps it would be clearer if we used a distinct term for area, so 2m2 would be 2 centiares.

Centiares?  Not even in France, where people already talk in ares, have I heard that term.

Any relation of Nessus?
No, that's the point. It's not a term in use but it might avoid confusion between square metres, metres squared and metre squares.
Riding a concrete path through the nebulous and chaotic future.

T42

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Re: Arithmetic that makes you cringe
« Reply #122 on: 02 October, 2019, 09:38:15 am »
Teach the buggers properly to start with would work better than introducing unfamiliar terms and expecting them to remember.

I reckon that a lot of the confusion in the media results from reporters having learnt the terms at school but forgotten them for lack of use.  I learnt physics in CGS units and was aware of MKS, but when SI arrived and everything got called after dead'uns I sort-of tuned out.
I've dusted off all those old bottles and set them up straight

Cudzoziemiec

  • Ride adventurously and stop for a brew.
Re: Arithmetic that makes you cringe
« Reply #123 on: 02 October, 2019, 09:50:52 am »
Wikipedia tells me CGS = centimetre, gram, second and MKS = metre, kilogram, second. To my mind these are the same system, just at different scales. Isn't half the point of metric/SI that it's easy to relate between different scales because everything goes up and down in 10s, rather than an assortment of 12s, 16s, 20s and whatever in Imperial (and various other pre-metric systems)?
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Kim

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Re: Arithmetic that makes you cringe
« Reply #124 on: 02 October, 2019, 01:11:03 pm »
I've got a container of industrial-strength glyphosate - gardening, for the use of.  The destructions specify dilutions in millilitres per hectare[1].  Interestingly this manages to make the chemistry and the maths equally scary.


[1] Fairly sure that's nanometres...