4 ms·

I'm going to go farther than you and say that US customary units are superior to metric in certain regards. A foot divided by three is 4 inches, a meter divided

by knolax 6y ago

I'm going to go farther than you and say that US customary units are superior to metric in certain regards. A foot divided by three is 4 inches, a meter divided by three is 3.3333333333333333333333333 decimeters. What annoys me is that the US gets singled out when the difference is one of degree, not kind. The UK still uses pints for beers, most countries still use their equivalent to feet in carpentry.

lopmotr 6y ago
This comes up a lot but is it actually a valid argument at all? In what real life situation would you want to divide 1 foot by 3 and get an integer as the result? If you're cutting materials, you usually want a given length, not 1/3 of whatever you happen to already have. So you're doing addition and subtraction, not division. Also, it only works when you're simultaneously converting from feet to inches, and only when it's 1 foot! It's no use dividing 1 inch by 3, or 10 feet by 3 or almost any other length really. Though you could do a little maths to get 2 feet / 3 = 8 inches. But 4 feet / 3 isn't called 16 inches, it's 1 foot 4 inches which is pretty complicated to work out compared to ordinary decimal maths.
- knolax 6y ago
  Not everyone calculates all the dimensions of what they're building in advance. Sure it's only convenient when you have integer feet divided by multiples of 2,3 or 4, but those are the first three primes so they're going to be common in a lot of operations. In which case the head math becomes: 4 feet divided by 3 = 4 * 4 inches = 16 inches (It's perfectly reasonable to stop here, your tape measure isn't going only say 1'4") = 16/12 feet + 16%12 inches = 1'4" vs. 4 meters divided by 3 = 4/3meters + ... = 1meter + 4%3/0.3 decimeters = 1.3meter + 4%0.3/0.03 centimeters = 1.33meters ... For each level of precision in metric you have to remember one additional digit, where as in the degenerate case for imperial you remember a constant number of digits at each step. Think of it as making multiples of the {1,1,2}th primes more convenient vs making the {1,3}th primes more convenient.
  - lopmotr 6y ago
    OK. I didn't realize that trick where you multiplied by 4 there. So it works when you're starting with any integer number of feet if you do a little multiplying. But I still doubt this has any practical use. Can you give me a concrete example where you or anybody you know has done this? How common is it?
    - knolax 6y ago
      I want to build a shed, I approximate human height as 7 feet because it's a nice even number. I want some number of beams equally spaced nailed onto the posts, I choose 4 posts because 3 and 4 are numbers people default to. 4 beams mean 3 spaces, 7/3=7x4 = 28inches. I nail the beams on every 28 inches. Can we agree that equally spacing 4 of something is a common operation? The metric example would be, 2 meters, divided by 3 = 0.333x2m = 0.666m But look at your tape measure and see which measurement is marked more promimently, an arbitrary centimeter precision measurement or an integer number of inches.
  - Symbiote 6y ago
    4 feet is very nearly 120cm, an equally likely (or approximate) measurement. A third of that is 40cm. Which was supposed to be easier? 30cm divides as well as 12in, and things that aren't nice numbers are easier to handle in cm or mm. Mark out every 4⅝ inches until you have a yard, then mark out every 12mm.
    - knolax 6y ago
      Most materials are sold in integer quantities of whatever the unit of measure is.
wildfire 6y ago
A metre divided by 10 is 10cm. A foot divided by 10 is 0.1feet = 1 13/64 inches. Contrived examples are easy.
- systemvoltage 6y ago
  IMO there is no question about metric system's usefulness especially because our counting system is in base-10. Metric system is tailored to that, whereas US ANSI system is tailored for base-12, which is the wrong base to work in.
- knolax 6y ago
  A foot divided by 10 is 1200thou. The nice thing about Imperial is that you can mix bases. And no, dividing by a multiple of 3 is not a "contrived example", it's literally the second prime. A multiple of 3 is by definition more common than a multiple of 10. You know what also doesn't make sense? The SI Prefix system, where you have redundancies like "A thousand megawatts" instead of just saying "A billion watts". Most languages already have built in prefix systems. In fact, South and East Asian languages space theirs every 10^4 instead of 10^3, making SI prefixes a clusterfuck to use. That's in addition to the fact that the prefixes themselves are chosen haphazardly. The ordering of Micro, Nano, and Pico has no discernible pattern as most people simply know all three words to mean small. Abbreviations such as M, m, and μ, are easily mixed up. Contrast that to thou and mil, which are easily remembered as abbreviations of thousandth and millionth. It's also easily extendable to an arbitrary precision.

by knolax 6y ago

lopmotr 6y ago

This comes up a lot but is it actually a valid argument at all? In what real life situation would you want to divide 1 foot by 3 and get an integer as the result? If you're cutting materials, you usually want a given length, not 1/3 of whatever you happen to already have. So you're doing addition and subtraction, not division. Also, it only works when you're simultaneously converting from feet to inches, and only when it's 1 foot! It's no use dividing 1 inch by 3, or 10 feet by 3 or almost any other length really. Though you could do a little maths to get 2 feet / 3 = 8 inches. But 4 feet / 3 isn't called 16 inches, it's 1 foot 4 inches which is pretty complicated to work out compared to ordinary decimal maths.

knolax 6y ago
Not everyone calculates all the dimensions of what they're building in advance. Sure it's only convenient when you have integer feet divided by multiples of 2,3 or 4, but those are the first three primes so they're going to be common in a lot of operations. In which case the head math becomes: 4 feet divided by 3 = 4 * 4 inches = 16 inches (It's perfectly reasonable to stop here, your tape measure isn't going only say 1'4") = 16/12 feet + 16%12 inches = 1'4" vs. 4 meters divided by 3 = 4/3meters + ... = 1meter + 4%3/0.3 decimeters = 1.3meter + 4%0.3/0.03 centimeters = 1.33meters ... For each level of precision in metric you have to remember one additional digit, where as in the degenerate case for imperial you remember a constant number of digits at each step. Think of it as making multiples of the {1,1,2}th primes more convenient vs making the {1,3}th primes more convenient.
- lopmotr 6y ago
  OK. I didn't realize that trick where you multiplied by 4 there. So it works when you're starting with any integer number of feet if you do a little multiplying. But I still doubt this has any practical use. Can you give me a concrete example where you or anybody you know has done this? How common is it?
  - knolax 6y ago
    I want to build a shed, I approximate human height as 7 feet because it's a nice even number. I want some number of beams equally spaced nailed onto the posts, I choose 4 posts because 3 and 4 are numbers people default to. 4 beams mean 3 spaces, 7/3=7x4 = 28inches. I nail the beams on every 28 inches. Can we agree that equally spacing 4 of something is a common operation? The metric example would be, 2 meters, divided by 3 = 0.333x2m = 0.666m But look at your tape measure and see which measurement is marked more promimently, an arbitrary centimeter precision measurement or an integer number of inches.
- Symbiote 6y ago
  4 feet is very nearly 120cm, an equally likely (or approximate) measurement. A third of that is 40cm. Which was supposed to be easier? 30cm divides as well as 12in, and things that aren't nice numbers are easier to handle in cm or mm. Mark out every 4⅝ inches until you have a yard, then mark out every 12mm.
  - knolax 6y ago
    Most materials are sold in integer quantities of whatever the unit of measure is.

wildfire 6y ago

A metre divided by 10 is 10cm. A foot divided by 10 is 0.1feet = 1 13/64 inches. Contrived examples are easy.

systemvoltage 6y ago
IMO there is no question about metric system's usefulness especially because our counting system is in base-10. Metric system is tailored to that, whereas US ANSI system is tailored for base-12, which is the wrong base to work in.
knolax 6y ago
A foot divided by 10 is 1200thou. The nice thing about Imperial is that you can mix bases. And no, dividing by a multiple of 3 is not a "contrived example", it's literally the second prime. A multiple of 3 is by definition more common than a multiple of 10. You know what also doesn't make sense? The SI Prefix system, where you have redundancies like "A thousand megawatts" instead of just saying "A billion watts". Most languages already have built in prefix systems. In fact, South and East Asian languages space theirs every 10^4 instead of 10^3, making SI prefixes a clusterfuck to use. That's in addition to the fact that the prefixes themselves are chosen haphazardly. The ordering of Micro, Nano, and Pico has no discernible pattern as most people simply know all three words to mean small. Abbreviations such as M, m, and μ, are easily mixed up. Contrast that to thou and mil, which are easily remembered as abbreviations of thousandth and millionth. It's also easily extendable to an arbitrary precision.