5 tomatoes
5 tomatoes
5 tomatoes
Ya know what. I like that tomato shit to remember the conversion. I like SI far more than US customary tho
If you want to convert between imperial units, going straight from feet to miles is impractical. You'd be better off knowing the chart of survey units, and they're all small numbers so they're easy to remember.
12 inches in a foot
3 feet in a yard
22 yards in a chain
10 chains in a furlong
8 furlongs in a mile
Of course, i know this because I do 3d art in blender and refuse to set it to metric.
Of course, i know this because I do 3d art in blender and refuse to set it to metric.
Did the metric system kill your family or something?
How do you do weight measurements? I noticed a lot of Americans use grams
Drugs are done in grams i think, methric
We use both. Body weight is in pounds, but nutrition is in grams.
In general we use metric more for smaller, more precise weights and imperial for everything else. I don't think I've ever heard anyone measure anything except cocaine in kilograms.
Of course, i know this because I do 3d art in blender and refuse to set it to metric.
You monster.
The dark side can be a pathway to many abilities some might consider ... stupid.
“In metric, one milliliter of water occupies one cubic centimeter, weighs one gram, and requires one calorie of energy to heat up by one degree centigrade—which is 1 percent of the difference between its freezing point and its boiling point. An amount of hydrogen weighing the same amount has exactly one mole of atoms in it. Whereas in the American system, the answer to ‘How much energy does it take to boil a room-temperature gallon of water?’ is ‘Go fuck yourself,’ because you can’t directly relate any of those quantities.” ― Josh Bazell, Wild Thing
"High. You put the stove on high."
I remember reading this quote a few years ago (probably Reddit), but I don't remember if attribution was given. Kudos to you CAVOK.
I love this quote.
It might be funny if it were true, but it's just a sad show of ignorance. It is exactly as possible in one as in the other for obvious reasons. It's just not as easy to memorize.
To be specific:
the only thing more aggravating than using imperial is having to listen to all the complaining about how metric is better. We get it, bro; it's out of our control at this point
"Because we are free men, we will be free to measure liquids in liters and milliliters... but not all liquids, only soda, wine, and alcohol because for milk and paint we will use gallons, pints, and quarts, god willing"
"How many liters are in a gallon, sir?" "Nobody knows."
"Why not use meters and kilometers?" "We sill, soldier. But only in certain unpopular sports like track and swimming."
My 2 main annoyances with the metric system:
First: The SI unit for mass is the kilogram. That's fucking stupid. A kilogram is 1000 grams, the base unit for something can't be "1000 of this other thing". Because the kilogram is the SI unit for mass, that means that a gram is, by definition, 1/1000th of a kilogram. The stupidity, it burns!
The second one isn't really an issue with the metric system, it's more when people are almost using the metric system then fuck it up, like the "Watt Hour" for measuring energy use. You know, there's already a way of measuring energy use: the "Watt Second", also known as "The Joule"
I am glad someone else has noticed this. Why is my TV's power consumption reported in kWh/1000 hours?
Because your power is billed in kWh. Figuring out the kWh cost of a 77 watt TV is straight forward, but a lot of consumer labeling standards are about quick and easy side by side comparisons as opposed to perfect application of units. Easiest way to give a comparison that's accurate enough and doesn't involve odd numbers is to convert that way.
Urgh. There's a unit for that, it's WATTS. That's literally 77 Watts.
it's more when people are almost using the metric system then fuck it up, like the "Watt Hour" for measuring energy use.
Energy is just so important to physics and engineering that it will be measured in whatever unit is most convenient to convert in that particular context: joules as the SI unit, watt hours for electricity usage, calories for certain types of heat or food energy calculations, electron volts in particle physics, equivalent tonnes of TNT for explosion energy, things like that.
I don't believe that "watt hours" are more convenient than joules, especially when they're not just watt hours but kilowatt hours or megawatt hours. At that point just use megajoules or gigajoules.
I can understand things like eV where the scale is so different that you'd have to constantly use tiny and unusual prefixes. But, for most other things like calories, it's just tradition rather than a well thought out reason.
I count a flat 8.
Metric is used all around the world, but comes from a quarter of it.
I use both in my wood shop. Sometimes it's easier to lay things out in metric or divide numbers, but other times it's easier to remember an imperial number to go make a cut.
All units of measure are abstract.
I like metric because it's structured around an abstract amount. Even something like Celsius is pretty abstract, because the freezing and boiling point of water changes depending on the atmospheric pressure. The measure of a second? Why is a second, 1 second long? Why is it 1/60th of 1/60th of 1/24th of a day? There's other stuff based on seconds too, like Hertz, which is literally "cycles per second"
I like to think about how abstract these things are, because if we were to ever try to communicate with a truly alien race, we couldn't really use numbers, because their base numbering system would be different than ours, their symbols for numbers would be different, their entire understanding of math and how to calculate stuff could be wildly different, possibly because they understand things we do not. We couldn't even say to them to communicate on a specific frequency of EM, because that frequency is based on Hertz, which is based on seconds, which is based on ????? IDFK (neither would they). We base everything we know on the world around us, and that's entirely unique to earth. We make so many assumptions about how things are because we've only ever experienced life on this planet.
The only thing that kind of makes sense is how many days of the year there are, because it's based on solid science about our solar system. It's still unique to earth, but at least it makes sense on a larger scale. Everything else? Who the hell knows. Why is a meter as long as it is? Who defined this? Why? What abstract Earth-based thing was this based on that other societies of individuals would have no point of reference to relate to?
It's wild we've made it this far, to be honest.
Anyways, I kind of got sidetracked... I guess all I'm really trying to say is that metric makes more sense than whatever the USA is doing. Even if it's just as abstract in its conception.
I'd assume that if we are ever communicating with aliens and trying to figure out each other's way of expressing numbers and doing math, dimensionless constants like pi, Euler's number (e), the fine structure constant, etc. will be important first steps. As you say, our units of measure are purely human inventions. But the ratio of a circle's circumference to its diameter is the same no matter what units you use to make the measurement.
I like you.
These are all good points. Thank you.
...which is based on seconds, which is based on ??? IDFK (neither would they)
"The second, symbol s, is the SI unit of time. It is defined by taking the fixed numerical value of the caesium frequency, ΔνCs, the unperturbed ground-state hyperfine transition frequency of the caesium 133 atom, to be 9 192 631 770 when expressed in the unit Hz, which is equal to s−1." https://www.bipm.org/en/si-base-units/second
I don't think that was the idea when the second was created.
The solar rotation cycle is naturally divided into 365 rotations of Earth (give or take), each daily rotation was divided into 24 segments called hours, each hour was further divided into 60 units called minutes, and each minute was then further divided into 60 units which we call seconds.
In the modern era, we have refined how we measure a second by a very stable natural phenomenon, the emissions of cesium (which we also refer to as an "atomic" clock). But we got there first by dividing one of Earth's rotations by 86400. It just so happens that 9 192 631 770 oscillations from cesium also equals 1/86400th of one rotation of Earth.
Additionally, neither a "second" nor even "one rotation of Earth" would have any meaning to someone who has never been to earth before.
their base numbering system would be different than ours, their symbols for numbers would be different, their entire understanding of math and how to calculate stuff could be wildly different
The neat thing about math is it’s built upon universal truths that exist independently of how you describe them. 1+1=2 regardless of how you represent those numbers. Even among humans we have plenty of different ways of describing numbers.
Also, the best thing about science is that physics works the way it does regardless of how you describe it. An atom of hydrogen will always have the same spectral peaks, regardless of what units you describe those peaks in.
It’s these kinds of things we consider when trying to communicate with aliens. Take a look at:
https://en.wikipedia.org/wiki/Pioneer_plaque
https://en.wikipedia.org/wiki/Voyager_Golden_Record
https://en.wikipedia.org/wiki/Arecibo_message
These messages will probably never be received, even if there is intelligent life out there. But if something intelligent does find these messages, they will probably determine they are artificial, and hopefully manage to decode some of it.
See, this is all fascinating for me. I love this stuff.
It's also a good exercise in recognizing the assumptions we make every day. I'm trying to get to a point where I can articulate my thoughts and I don't have to struggle through the curse of knowledge.
I think one useful comparison would be to convert their measurement of the speed of light to our measurement and vice versa. They will use different units of distance and time, but the values themselves will be proportional unless they live in a black hole.
That could work for velocities, but any measure of distance is based on our notion of time, like "light year" (the distance light can travel in one rotation of the Earth around the sun), which is relative.
Even an AU is the distance from Earth to our sun.
To be fair, we don't really have another point of reference with which to measure stuff.
A good way to portray distance could be a blip the length of time it would take light to travel that far. Like an RF signal that lasts as long as it would take for light up travel from one edge of an object to the other edge of the object.
... It's a difficult problem to try to solve even as a mental exercise.
The only positive thing I see about imperial is that things are easily divisible by 3 and 6, but that's about it. Then again, if doing the same with metric, you're usually fine rounding to the nearest millimetre, and if that isn't accurate enough, it's probably not supposed to be done by hand anyway.
Base 12 is easily divisible by 2, 3, 4, 6 and 12
5,280 ft in a mile is fucking nonsense though
It's not nonsense, just old and focused on priorities that don't matter anymore. A mile was initially a thousand paces. So you send a group of people out, one counts each time their right foot takes a step and after a thousand times they build a mile marker. Bam, roman road system. 1000 strides per mile, 5 feet per stride.
Later the English used the unit as part of their system of measurement, and built the furlong around it, which is the distance a man with an ox team and plow can plow before the ox need to rest. A mile is eight furlong. This got tied into surveying units, since plots of land were broken up into acres, or the amount of land an ox team can plow a day.
When some unit reconciliation needed to be done, they couldn't change the vitality of oxen, and changing the survey unit would cause tax havock, so they changed the size of a foot.
All the units and their relationships were defined deliberately and intentionally. They just factored in priorities that we don't care about anymore.
I think a mile is specified in terms of 'chains' not really feet or yards. Feet and yards are meant for measuring smaller stuff, like the size of a foot, or a courtyard.
The 'chain' was a specific surveyors tool for measuring larger land areas. I imagine defined to be a length of physical chain practically manageable by the surveyor - probably pre-dating optical / triangulation methods before lenses got cheap.
I think an acre was then defined as 10 square chains or something.
But go back in time far enough and different jurisdictions have different lengths of standard chain, so different miles and acres derived from it. But it doesn't really matter because if you were buying land in Scotland, then you'd probably want to use a Scottish surveyor and his big long chain.
The nautical mile is then a whole other kettle of fish.
Because there's a extra system of measurement change hiding in the middle. The Inches, Feet and Yards system (with the familiar 12:1 and 3:1 ratios we know and love), and Rods, Chains, Furlongs and Miles system. Their conversation rates are generally "nice", with ratios of 4 rods : 1 chain, 10 chains : 1 furlong, and 8 furlongs : 1 mile.
So where do we get 5,280 with prime factors of 2^5, 3, 5 and 11? Because a chain is 22 yards long. Why? Because somewhere along the line, inches, feet and yards went to a smaller standard, and the nice round 5 yards per rods became 5 and 1/2 yards per rod. Instead of a mile containing 4,800 feet (with quarters, twelfths and hundredths of miles all being nice round numbers of feet), it contained an extra 480 feet that were 1/11th smaller than the old feet.
If an alien species has 12 fingers to our 10, would they work in base 12 as normally as we use 10s? Like would their whole system end (or start) with a 0 or equivalent and not end all different?
My maths coherence is too high-school for this thinking, but now its in there.
Base 60 can do 2, 3, 4, 5, 6, 10, and 12.
I've banged on about this at length before. I prefer woodworking in inches because I have to divide by 3 and 4 a lot more often than divide by 5. It turns out that the fractional inch system evolved alongside woodworking for a very long time and it solves a lot of the problems woodworkers actually face...as long as you're not a European scraping in the dirt for something to feel superior about.
I do woodworking a bit too, but I normally just do the slanty ruler/tape trick to divide any straight parallel face into n equal lengths. I hate all forms of mental arithmetic; I also avoid measuring as much as possible too. Maybe that's why everything i make is so shit.
I guess if you're mass producing things you can't just manually mark off each and every part though - but even then I'd probably want to work to a template rather than to measure.
It's funny how the biggest argument for metric is that it's so accurate but in real life use it degrades to "close enough". My main problem with metric is that I can't get my pencil that sharp.
What are you even trying to say here? Yeah, in real-life use we use "close enough". I don't need to know that it's 1,546 metres to the nearest supermarket. 1.5 km is close enough.
But nobody is suggesting it because it's "so accurate". Any system can be accurate, depending on how many sig figs you use. The advantage of metric is on how easy it is to convert between different scales. Use millimetres, metres, or kilometres for the appropriate case, depending on the need you have for precision. And just move the decimal point if you decide you don't need as much precision...or need more. In archaic measurements, you can't do that. If you've got 342 feet and decide you actually only need to be accurate to the chain, you have to memorise the arbitrary number of 3 feet to a yard, and 22 yards to a chain, and divide 342 by those numbers, to arrive at 5.2 chains.
It's accurate when you need it to be and gets out of the way when you don't. And if you do need the accuracy, you have a unit that doesn't need fractions.
How is "accurate" an argument?? You can use any unit with any amount of decimal places. The argument is that it's regular. You learn the prefixes once and apply them to length, volume, weight, ...
The biggest argument for metric is that it's consistent. It takes 1 calories to heat 1k of water by 1 degree. State something similar in imperial units.
Most standard measuring tapes have 1/16th of an inch as the smallest fraction on the tape. 1mm is 1/32nd Which is one is "close enough"? Lol
Edit: 1/32, not 1/64
What about a nautical mile?
The only metric to imperial conversion I remember is kilometers to miles since it's pretty close to the golden ratio.
Even if you don't remember that the golden ratio is 1.6 and a bit, you can approximate it by using successive terms of the Fibonacci sequence.
1, 1, 2, 3, 5, 8, 13 ...
So 8 miles is about 13km (actually 12.87)
2.2 pounds per kilogram. For a rough conversion just multiply or divide by two. For a more precise conversation do the same thing, then wiggle a decimal and do it again.
Its 2.54 cm to the inch. Its close to 2.5 and as an engineer in America I am stuck doing that conversion a lot
If it makes you feel any better, most pipe standards around the world are based on the American system, as well as bloody valve coefficients.
I am far too aware that 1" is 25.4 mm :(
And I'm in Australia. Grumble
A meter is a Baker's yard. 3 free inches!
Forma me it's the yard. It's so close to the meter its ridiculous. I just ignore the difference an treat as the same. One yard = 0.9144 meters
I usually just go with 1.5 because adding half/subtracting a third is way easier to do in my head, and I'm not worried about a ~10% error in casual conversation.
I just go with 1.6 because its still easy enough to do in your head.
Eg. 60mi = 60 + (60/2) + (60/10) = 96km
Me watching a BBC TV show: "The suspect's home is five miles away."
shocked pikachu
there's a very important video on the measurement rules in the UK, if you haven't seen it: https://www.instagram.com/reel/DNh9z3IzG8t/
Without seeing it let me guess: If it is serious --> metric units and if you want to confuse customers --> imperial
Just remember God giving you a single grain of sand. "One thou sand".
Not a easy to remember as 5 tomatoes.
Imperial actually makes sense if there system was invented by someone who only had polyhedral dice to count with.
And to remember the number of yards in a mile: 1 San Francisco
One-seven-six-oh
At first I thought that's how Americans measure it - in San Franciscos. But given how "San Francisco" doesn’t sound like "One seven six oh" I'm not sure if they don't.
It's not a good tip, but this is how I hear it:
1: One
San Fran: Seven
Cisc: Six
O: Oh
I just came up with it off the cuff, but I may use it going forward. I've never been able to remember feet or yards in a mile.
Also, we only measure length in bananas and fractions thereof.
If Americans don't stop the foot thing soon I will bring back the havoc and destruction of using local measure!!
https://en.m.wikipedia.org/wiki/German_units_of_measurement
No I will not define it. I will just tell you I ran 2/3 mile and that I am prussian, now you have to look it up, convert it to meters, convert that back to your mile and then you know what I am talking about.
Btw this mile is way easier to remember because a mile is 24000 feet.
Whose feet‽
Mine, but I didn't cut my toenails, so today's its 1/26th foot longer that the normal foot.
It does not matter, all feet have roughly the same size.
-- the shoe company
Not in defense of the imperial system, but if you're curious why it's so arbitrary, it's a crazy story about untangling a ton of proprietary guild measurements. The mile itself isn't quite proprietary (it was defined as 8 furlongs, and you can blame the English for ruining a perfectly good roman measurement) but they needed to make it a certain number of chains, rods, yards, and feet, plus a few other obscure measurements I forget about. Naturally that results in a stupid conversation rate (mostly vs yards and feet since it was basically a different system).
Why we still use it, dunno. I can see an argument for keeping feet and inches for things like carpentry (in the similar way I like hexadecimal in programming) but miles is not that. It's about as logical as this point as fahrenheit, which is to say it's outdated nonsense.
To me, Fahrenheit is a lot like inches and feet for carpentry. As in it's fine for things like describing the weather and setting my house's thermostat. It mostly falls apart for must other things, though it's still okay for cooking and baking. From a scientific perspective, any temperature scale that isn't zero at absolute zero is nonsense, so it's pretty much Kelvin or bust.
In traditional carpentry inches and feet make sense because of the high divisibility. We don't get as much benefit from that now though.
We still use hex with computers because that's what they're made using (rather binary, but hex is just a natural group of binary digits). The usage of binary is ultimately more grounded in the objective than the usage of base 10 in the SI system. Nature dictates the relationships between the units, but we pick the quantities so it works out to a nice base 10 set of ratios.
Base 2 naturally arises when dealing with information theory that underpins a lot of digital computing.
Say what you will about the imperial system, but you can pry binary, octal, and hex from my cold dead hands.
Arguing with the imperial system is like arguing with my mother. She knows her ways and methods are insane, but she will try to explain why she needs each of those eight furlongs. Either ADHD will steal her ability to finish the explanation or the audience will perish from exhaustion. And she still will be the smartest person in the room.
You don't have to use it though. Reject it.
Did someone say feet?
So whose foot exactly?
Cousin Merle's (including toenails).
Could also be his dad's feet, but then it's only the toenails.
Some European king or another. We didn't invent the system, we just decided it was too expensive to bother with changing it.
Why not just keep it simple and use the 5.4 microseconds * speed of light approximation? People just love making things overly complicated.
Especially when you just set c = 1
It's not helpful for us seriously distracted people. To remember a number, I must remember a smaller number. Damn, how many was it? Three tomatoes? Eight tomatoes?
Was it even tomatoes? Maybe it was potatoes?
Somewhat related, but I have the worst time trying to convert numbers in my head from long scale in Japan (used to be used in the UK as well) to how it's used in the current English speaking world. So basically they put four zeros per comma as opposed to three, and the names of the numbers reflect that. 1, 10, 100, 1000, and 10000 are all unique number names, but after that comes 10 ten thousands, 100 ten thousands, and then 1000 ten thousands before a new number name at 1,0000,0000 (or 100,000,000).
It wouldn't be so bad to just memorize that 100 thousand is "new number name" if that's all it was, but numbers like that in daily life are pretty much used to talk about money (or somewhat less commonly populations). So once I get the actual number I have to divide by about 100 (or 150, depending on the strength of the yen vs dollar) to think about what it actually means in units I'm used to, like seeing an article saying a government project costs 1.2 billion yen doesn't mean much until I think about it like 12 (or 8) million USD instead. So I can never really use big numbers in conversation without manually counting zeros in my head.
It helps to memorize million and billion both ways since those are what you'll be using most, and are good signposts.
Yeah I'm sure it's not as difficult as I'm making it out to be but it never seems to stick. It's just as simple as 2 numbers: "million = 100 ten thousands" (hyaku-man) and "billion = 10 hundred millions" (juu-oku).
Let's just say there a lot of frustrations I have with the language even after decades of studying.
I wish we had a metric inch because the fuzziness can be useful.
"How small do you need these veggies diced?"
"2.5cm ish" vs. "about an inch"
I feel like the implied margin of error is much larger for inches, which make them useful for many things where precision isn't necessarily desirable (hemming, wargaming, moving furniture, etc..). If I'm wargaming having a limit on rounding is useful (half an inch - either round up or down), assuming I'm playing at a scale that uses inches.
Feet I have no use for, with one exception - adult human height between 5' 2" and 6' 2". There I find metric too precise (whereas to the nearest inch accounts for variance in sole thickness, hair volume, etc.).
I wasn't raised on imperial (and I'm baffled that people younger than me in the UK still talk about stones. Sixteen stone is fat, sure, but I've no idea how fat if not told in kilos) but I find inches to have their uses.
Also miles for cars - because common speeds are ~60 and ~30 mph so a road sign effectively gives the time to arrival (e.g. 13 miles on a motorway = about 13 minutes). I don't use them for actually measuring distance on a map but they're handy when driving.
Why not say ‘2-3 cm’ for the first one? Or ‘a couple centimeters’? It doesn’t feel too different from saying ‘about an inch’ to me
Taking it even further who the fuck uses inches or cms for vegetable cutting measurements anyway, it's like, one or two fingers thick
It's to do with how I think about numbers, rounding, and margins of error. I don't know how to express that better, I'm sorry.
I was not raised using inches for anything. It's not a cultural thing, it's a use case I've found them useful for.
We kind of do have metric inches, insofar as machinists work in 'thou's (thousands of an inch) But that's kind of specialist
Thousandths of an inch are also used in some engineering applications and are called "mils." Not to be confused with millimeters.
Do we have meter cola?
Oh, get off your high horse
Your basic unit for speed is m/s, but for most day-to-day purposes you use km/hr. The conversion between the two isn't even an integer!
Not only that, but your system, by virtue of being decimal, inherits all the shortcomings of our quite flawed numbering system. You can't divide something by the second smallest prime number without breaking out repeating decimals.
In my opinion, a good measuring system would make up for those shortcomings instead. It should be divisible by at least the numbers you can count on one hand. Decimal covers 2 and 5, so ideally the measurement unit would cover 3 and 4. So that would be a base 12 system. Technically 4, being 2², would be covered too, so 3 would do just fine. Ta-da! 12 inches in a foot, 3 feet in a yard.
My ideal would be 21 though, get that 7 factor
If you like intervals of 1000, you'll be delighted (or mortified like me) to know that 7×11×13 is almost exactly 1000 (it's 1001)
Not only that, but your system, by virtue of being decimal, inherits all the shortcomings of our quite flawed numbering system. You can't divide something by the second smallest prime number without breaking out repeating decimals.
What's more 0.203 cm or 0.291 cm? How about 3/8" or 19/64"?
How far is 1/3 of a mile? 1/3 km is 333m. How about 1/9? 1/9 km is 111m How long is 10 x 5/16"? 10 x 3.1cm is 31cm
Yeah, a foot breaks down easy in whole inches with many factors, but that's about it
Most people who deal in imperial units know off the top of their head that 1/3 of a mile is 1760 feet. They don’t have to calculate it. After a while you see that number come up often enough and it’s committed to memory.
I’m not saying that metric isn’t better, it is, and I wish we would hurry up and switch to it. I’m just saying that the numbers involved aren’t a handicap once you have worked with the imperial system for a while. If you have a set of sockets that you work with every day, you know instantly that 3/8” is bigger than 19/64”. Hell, even 5/16” is bigger than 19/64”.
And, you must admit, 333 meters is not one third of a kilometer. It is one third of 999 meters. The number 5280, for all its awkwardness, is beautiful in the sense that it is evenly divisible by 12, Meaning that it can be exactly divided into quarters, thirds, or halves without a fractional part.
You can also count on your finger joints (excluding thumbs) for base 12, too
Okay so to fuck us all over we can go to base 9.
We can divide evenly by 1,3,9. But actually remember:
1/9 - .11111
2/9 - .2222
....
8/9 - .8888
So easily divisable right? /s
Imagine being so close minded and bad at math that you can only think in base 10 and feel the constant need to degrade people who are good at math in different bases
What a weak argument. You shouldn’t have to be good at math to do basic calculations in daily life. Metric is much more accessible in this regard. Even if you lack math skills it is easy to understand.
Did you read the words I wrote? It looks like youre responding to a "imperial units are better than metric" strawman which you may notice I didnt say or even allude to
I hate to point this out, and will likely be shunned for it - but it is base 12 and kinda easier.
Found the Summerian astronomer.
Metric will never recover from not being base-12. Ease of use and intuitiveness suddenly trumps "objective" design. We'd have metric time right now, smh.
We don't count in base-12. Redesign the numerical system first and get it adopted world wide. I'll wait.
Base 60 is five times better again
Let me tell you about base 5040
If only they made a meter equal a yard. Then we could all be bilingual.
If there's a better base than 10, it is a power of two.
Nah, highly composite number. A product of multiple primes. 10 is 2 and 5. A power of 2 is just multiple 2s. 12 gets you 2, 2, and 3. 60 adds a 5.
I've never once had to convert miles to feet or vice versa in nearly 40 years (besides a couple test questions in school). It's a total non issue in the whole SI vs US system debate