I suppose they had little booklets. A bit like the logarithmic tables that people kept for complicated calculations. Maybe they were issued on the first day of school or something. People would keep them all their life and look at them surreptitiously whenever they had to convert units.
Metric:
10 mm = 1cm, 100 cm = 1m, 1000 mm = 1m, 1000m = 1 km.
1 cm3 water = 1 gram
1 Watt heats 1 gram of water 1 C°
1 dm3 water = liter = 1 kg
1 m3 = 1000 kg = 1 tonne
Imperial:
1 mile = ?? yards = ?? feet = ?? inches
1 ton = ?? stone = ??punds = ?? oz = ?? grain
1 Galon = ?? pints = ?? fluid ounce
1 inch3 = ?? grain = ?? power to heat ?? fahrenheit
There is no system to any of these, they are unscientific and impractical.
How does Imperial still have any relevance as a measurement system?
60 miles = 318 Kilofeet
That’s exactly how I’ve memorised imperial as well. We must have used the same manual.
Yes, you could say Imperial is easier, because you’d never calculate anything in your head, you ask Google.
But how did that even work before we had Internet?
I suppose they had little booklets. A bit like the logarithmic tables that people kept for complicated calculations. Maybe they were issued on the first day of school or something. People would keep them all their life and look at them surreptitiously whenever they had to convert units.
1 barrel is 734 ounces. Whoo what a handy table. LOL ;)
I lived someplace with an old sticker inside a cabinet door with a bunch of basic, useful conversions. It was neat.