Working out the square metres

[GeorgeandAde]

Hi.
Were thinking of having a flat roof refelted and want to get quotes.
Would any mathematician here know how many square metres are in an area of 24ft x 20ft please?.
Many thanks.

 

[ProfJohnL]

According to Google


A linear foot is the same as 0.3048 meters

So your 24ft = 7.3152
and 20ft = 6.096

7.3152 x 6.096 = 44.5934592 sqM or call it 44.6 sqM.

 

[otherclive]

According to Google


A linear foot is the same as 0.3048 meters

So your 24ft = 7.3152
and 20ft = 6.096

7.3152 x 6.096 = 44.5934592 sqM or call it 44.6 sqM.

My son has a balcony from his first floor lounge which leaks into the garage and workshop as it’s paving slabs over felt. The quote for 60 m2 EPDM and some compatible tiles is £8000. A large chunk of that was the EPDM including three days to fit.

 

[GeorgeandAde]

Thank you prof and otherclive.
Very helpful👍.

 

[Beachball]

Thank you prof and otherclive.
Very helpful👍.

Hi Georgeand Ade Rough week so maths not up to spec, stick with answer from Prof and otherclive.

 

[GeorgeandAde]

Thank you Beachball.
I did try google first but couldn't make head nor tail of it.
The prof. explained it perfectly.

 

[Thingy]

Despite another thread decrying the use of apps, me included, I can thoroughly recommend a free app called Convertpad. Its like the Zeus Charts of the modern era.

 

[Sam Vimes]

Zeus Charts - that's a blast from the past. I still have my Log Tables from school and my 10" sliderule.

I can remember taking one exam at college where we were issued with books of random numbers. I didn't get the irony at the time that all my friends also had the same book with the same set of random numbers.

We also had sessions dedicated to approximations where we were given tasks and had to work out the answer with no tables, no sliderules etc. just pencil and paper - they wouldn't trust me with a pen - and its amazing how close you can get with practice, knowing when to over estimate and under estimate which balances things out.

Still comes in handy when the wife says how big is 10cm and I'm tempted to say just less than 11cm instead of 4 inches.

So, 1 sqm is just under 11 sqft

 

[Thingy]

My wife is the same. Had no ability to estimate length whereas i am very accurate with that. Btw, i still have my old Zeus charts. Priced one shilling. I wonder how many here can use a slide rule.

 

[audiorob]

A blast from the past reminds me of the certificates I obtained at secondary school maths club for using the calculator- a bit the size of a small shop till (AKA Open all hours!) with a handle to wind forward to add and backwards to subtract and a carriage to slide left or right to multiply or divide. Now I have a phone app for the same task without the physical exercise! Showing my age I'm afraid!

 

[Hutch]

My wife is the same. Had no ability to estimate length whereas i am very accurate with that. Btw, i still have my old Zeus charts. Priced one shilling. I wonder how many here can use a slide rule.

I still have my Thornton Comprehensive slide rule and two Zeus books one the Metric version.

 

[Hutch]

Despite another thread decrying the use of apps, me included, I can thoroughly recommend a free app called Convertpad. Its like the Zeus Charts of the modern era.

I am not against usefull apps like conversions etc, it's app for controling your cooker and the latest, controlling your pressure washer. .

 

[ProfJohnL]

I am not against usefull apps like conversions etc, it's app for controling your cooker and the latest, controlling your pressure washer. .

I also think there is another aspect on reliance on apps, There is a tendency to rely on them too much and to believe them implicitly, One things for sure you can eb wrong to many decimal places.....

Having had to use the discipline of a slide rule and tables (to some extent) part of the process was to understand the size or values of the figures you were using, I can remember occasions where the a guestimate would indicate the scale of the result, and the tool the precision. If here was a mismatch it prompted you look again for any mistakes.

Using that method I discovered a mistake in Kemps.

Todays button pushers don't always have a feel for scale of a number.

 

[Jcloughie]

I went for an exam for a job in around 1980. No calculators were allowed. But slide rules were. I got hold of a slide rule and crammed how to use it in a couple of days. Came to the exam, it wasn’t needed. (But I got the job).

Around 1975 me and my partner had the opportunity to tender for a large sub contract on a hypermarket and 8 shops, we only had 2 days to to do it. Calculators were an arm and a leg then, so I got one on appro. We had to keep going out for aa batteries, it was expensive. Also it got ridiculously hot. We found out we were the closest to the QS’s target, but a cheaper quote got the job. But he went in too low and had to walk away.

Such is life.


John

 

[otherclive]

I also think there is another aspect on reliance on apps, There is a tendency to rely on them too much and to believe them implicitly, One things for sure you can eb wrong to many decimal places.....

Having had to use the discipline of a slide rule and tables (to some extent) part of the process was to understand the size or values of the figures you were using, I can remember occasions where the a guestimate would indicate the scale of the result, and the tool the precision. If here was a mismatch it prompted you look again for any mistakes.

Using that method I discovered a mistake in Kemps.

Todays button pushers don't always have a feel for scale of a number.

I still keep my slide rule, BSI 9 variables slide conversion chart, and a book of tables/data/formulae handy in my office draw. The bamboo slide rule by Ricoh, who now sponsor stadiums, has a inner section very useful for lightly inputting key data at exam time. Even on my 1976 post grad exams we had to use slide rules and tables. But to be honest the calculators at that time were not that user friendly and were slow.