Andy in Germany
Legendary Member
- Location
- Rottenburg am Neckar
km = (mi/2) + (mi/10) + mi
mi = (km/2) + (km/10) (plus a little bit for luck)
Could you do and example of this so I can understand it?
km = (mi/2) + (mi/10) + mi
mi = (km/2) + (km/10) (plus a little bit for luck)
Of course, it’s only those who insist on using kilometres that make this necessary ;-)
Could you do and example of this so I can understand it?
Could you do and example of this so I can understand it?

Maybe I have a weird brain but I find this really easy. It comes from years of running 10ks and half marathons, and riding 100km and 100 mile rides and thinking about such things to pass the time. Other people have their own pet methods and prefer them. I'm not saying this is a good method or that others should use it. It just happens to be what I do. If you don't like it, fair enough, I'm not asking you to.
If I might answer?
It's actually a rather good system involving simple sums. Let's take a distance of ten miles to be converted into kilometers.
You can leave yer boots on if yer've size ten(UK) feet/safety footwear.If I'm measuring a wall, I think I'll carry a tape measure rather than take my boots off...
If I'm measuring a wall, I think I'll carry a tape measure rather than take my boots off...
Thanks, that's really helpful.
It's not a matter of scepticism about the system; more that I can't generally understand formulas unless I see an example, and often even then I don't really understand what they "mean". I'll learn a formula by rote and practice obsessively because I know that if I follow the steps and keep the units, the number at the end is usually what the examiner wants.
As an example I'm currently practicing the formula for amps, volts and ohms. Fortunately I can generally select the correct formula because here they use a visual system, but I still don't really understand what I'm doing.
However, a week after the exam I probably can't use the formula any more: I'll have forgotten it entirely.
Or you could just remember 10k is about 6 miles, and figure from there?
Eh? You need to round it *down* a bit, not up. 10km = 6.214 miles.half it, add a quarter and round up a bit... is my method of getting near enough.
Eh? You need to round it *down* a bit, not up. 10km = 6.214 miles.

As an example I'm currently practicing the formula for amps, volts and ohms. Fortunately I can generally select the correct formula because here they use a visual system, but I still don't really understand what I'm doing.
However, a week after the exam I probably can't use the formula any more: I'll have forgotten it entirely.
Is it still V=IR ? Ohm's Law. Unlike you I've remembered that for many years, but I'm definitely not a visual learner. I was always very good at memorising things and maths and physics came very naturally to me.