I am enjoying this one!
Here in the UK, there is quite a "Generation Gap" when it comes to Weights, Capacities and Measures. I belong to the older generation which grew up with Imperial measures (Feet, Inches, Quarts, Gallons, Ounces, Pounds, Stones. etc.) The very word "Imperial" tells us that it all belongs to a much earlier time, based on systems created when Britain had the biggest empire the world has ever known. In other words, it's way out of its time.
However, as a former engineer I used Metric measures in my work and grew used to converting stuff in my head (approximately) in order to communicate with customers and suppliers, before giving an accurate written quote. This gave me a very flexible mind, I found.
Examples (Imperial, not necessarily US) would be, if my memory serves me well enough: -
One inch = 2.54 Cm. (work it mentally as 2.5, use 10cm. and divide result by 4)
One foot = (roughly) 30 Cm.
One gallon = 4.54 liters.
One Kilometer = 5/8ths (0.625) of a mile.
Some of the old Imperial measures are really archaic, involving Furlongs (8 to one mile), Chains, Hundredweights and others I have mercifully forgotten.
All of this may be the reason why some British and American engineers and scientists can seem a little detached from reality sometimes. We are known to mumble inaudibly to ourselves when working out some cross-dimensional problem.
