I remember a Mexican guy complaining about girls who were "sesenta, noventa, sesenta", and it took me the longest time to puzzle out that he was talking about their measurements -- in centimeters. In other words: fat girls.
Of course, we have the same pattern in English (the infamous 36-24-36), but the 60-90-60 reference completely threw me off! (It's not fair to hit me with both a different language and a different set of units all at the same time -- especially after a few beers!)
I'm civil engineer from Croatia. In my everyday work I use Metric (SI) and occasionally Imperial units. After reading all these posts I have to admit I'm disappointed with how some people are reasoning. System International (SI) is implemented throughout the World to prevent mistakes. It has only 7 base units and 22 derivatives. In practice you mostly deal with basic units.
For example, milimeters (mm), centimeters (cm), kilometers (km) represent are derivatives of basic unit - meter. Letters m, c, k are used as prefixes, and denote fractions of meter (c = 1/100 m m = 1/ 1 000 k = 1 000 m, M = 1 000 000 m). His basic advantage to other system lies in fact that it's based on decade system.
In Imperial system for example: 1 ft = 12 in but 1 in = 0,08333 ft
Also 1 yd = 3 ft but 1 ft = 0,333333 yd
As you see, Imperial system is mathematically prone to mistakes, especially when calculations are made by computer (rounding).
In practice we also use inches (zoll), acres and similar old units, so they couldn't claim them as USA or UK specific. Origins of some units going way far to Middle age Europe.
I agree, Americans and Britons were "juggled" in this case, but they have to get used to this imposed system as in other situations we (other Europeans) had to adopt British or American standards.
For example, in building industry whole Europe adopts Eurocode standards, which are mainly influenced by BS standards. USA are adjusting their standards to Eurocodes, Australians and Japanese too. In other words, welcome to globalization.
Personally, I hate reading technical books written by American authors (not all to be correct), because of total inconsistency regarding use of units. It doesn't matter whether you use one or other measuring system, as long as you are consistent. You may find units written as full words, or what's even worse, abbreviated units expressed in plural, or mix of SI and IMP units.
For example, what is 5 fts? It could be read as 5 ft times 1 s, what doesn't have any sense. Or what is 5 lb/m ?
PS.
Gabriel, there's nothing wrong with expressing rounded numbers in everyday situations (translations). It's bad and dangerous when these mistakes lead to human losses. In many cases it's result of total ignorance to other system.
<<For example, what is 5 fts? It could be read as 5 ft times 1 s, what doesn't have any sense.>>
It doesn't make any sense to me either. If it's supposed to be short for "five feet", that would still be abbreviated as "5 ft" -- no s.
Or what is 5 lb/m ?
Five pounds per meter. Now this IS familiar to me, as we used this in medicine all the time. There's really no problem with mixing your systems like this, since the measurements are two completely different things (weight and distance). It was not uncommon for us to speak of medication dosages as one milligram per pound (the canine dosage rate for Benadryl) or 1 cc for every ten pounds (the dosage for euthanasia solution). If you like you can convert them to their equivalents in straight metric -- about half a milligram per kilogram or 1 cc for every 4 kg, but they come out to the exact same thing -- and we tended to weigh our animals in pounds and dose them with medications labelled in milligrams or micrograms or cubic centimeters.
There is no point in trying to tell owners how to dose animals using kilograms, since they wouldn't really have any clear conception of their dog or cat's weight in kg, but they usually know how much it weighs in pounds. So you stick to the measurements that make sense to them. (There really isn't any common, everyday non-metric equivalent to milligrams, being so tiny, so that poses no similar confusion.)