There's a difference between accuracy and precision, and there's also a difference between consistency and convenience.
It's the reason I might choose Ruby over C (convenience - Ruby was designed to be centred around the human, like many Imperial measures, and non-decimal currency btw), or use feet instead of metres (because I have feet that are, astonishingly, close to a foot long) or any other number of examples where metric is not the best or a better choice.
I'll leave you to divide 100 by 3 or 12 so I can buy 1 or 4 of those dozen eggs you're selling with £1 while this Victorian street urchin who's had little to no schooling beats you at it because they're using a non-decimal currency with more factors…
tl;dr People in the past weren't stupid, they just had less access to the technology required to maintain a metric or decimal system in a widespread number of contexts. The existence of such technology does not obviate their usefulness.
Your Michelin starred restaurants are doing alright compared to which country? Many countries are doing better than the US there, both per capita and even absolute.
It explicitly means that dividing by anything other than a power of 2 is hard. One third of a quart is... quick, how many cups? Okay, now what's that in ounces?
And that's just dividing by three, which is a pretty normal thing to want your measure system to handle.
Base 10 measures are directly compatible with the number system. Even though metric doesn't admit factors other than 2 and 5, because it's decimal I can still confidently and quickly tell you that 1/3 of a liter is 333ml. Or that 1/7 of a liter is 142ml - and if I want to check that I can just type 1000/7 into a calculator and read off the result. How many ounces in 1/7 of a quart?
How do you expect to use a calculator with dough on your hands?
> How many ounces in 1/7 of a quart?
Why are you trying to divide volumetric measures by weight? You need to measure the liquid's weight and divide that by 7. Liquids differ in weight per unit volume.
:-) There are volumetric and weight-based ozs. There are 128 ozs in a gallon. That is 16 cups to a gallon with 8 ozs per cup.
The problems that the poster one-higher stated are trivial. 128/3 = 42 2/3 ozs. 1/7 of a gallon in ozs is 8/7 * 16 in ozs = just over 18 ozs. 1/7 of a quart is just that answer divided by 4, 4.6 as an off the cuff calculation.
That's a good point, the good old fluid ounce or "floz" as I would read it as a child. I did used to wonder who Floz was and what she'd done to deserve having her name in so many recipe books :)
That's funny! I just did an image search to see if anyone had ever drawn a picture of her. The first three images on google for floz were a shot glass measuring out 2 ozs of bourbon, Cetaphil, and a container of clear edible glue!
You seem to be hung up on converting between place values. When you say, quick, how many cups in a pint" it's like asking "quick, how many grams in a kilogram!" You'd look at the person funny.
It's only self evident because you know the answer. How is knowing kilo = 1000 that much different than pint = 2 cups = 16 oz? They're just powers of 2 instead of 10.
Because a kilogram is still just "grams"; the relation between kilo-, milli-, etc. is linear. Metric units allow you translate, for example, 1 liter to milliliters in just one jump. And it's not like there are that many prefixes to remember.
The relationship isn't linear, it's logerithmic, just as the us volumetric measures are.
There are more steps in the power-of-two measures, but hardly anything unreasonable.
The real usability of the metric system, which I think you're getting at is that those prefixes are reüsable between all units, whereas in the us customary system it's no holds barred and everything outside the volumetric is arbitrary.
That said, with length, it is nice having units that break apart evenly at 2, 3, 4, and 6; but I don't think that's quite enough to redeem it.