It’s called an example. Want another one? How many laps do you need to run on a 400 m track to run a 10k? How many people can you serve with your 2.5 kg steak if everybody needs to get a 250 g steak? Need more?
Heres the thing, your examples suck because there are no good examples. Almost no one needs to make conversions in their daily lives and those that do have charts and calculators.
How many 39 ft rails do you need to build a 100 mile railroad?
Why on Earth would I ever do that?
If I was a rail engineer, I would have a chart (or a calculator if its past the year 1980)
Can you divide 1000 by 39 quickly and easily?
It’s called an example. Want another one? How many laps do you need to run on a 400 m track to run a 10k? How many people can you serve with your 2.5 kg steak if everybody needs to get a 250 g steak? Need more?
Heres the thing, your examples suck because there are no good examples. Almost no one needs to make conversions in their daily lives and those that do have charts and calculators.
Life is not a math problem.