# Why kms?

#### MartinQ

##### Veteran
We have the Babylonians and their base 60 system to thank for that. But we express it in base 10,

There are those who think we'd be better off switching to base 12 numbering http://www.dozenalsociety.org.uk/ Now that would be fun!
And we have the Italians (Leonardo de Pisa) <- {Indians,Muslims} to thank for the base 10 decimal notation, otherwise we'd all still be using Roman numerals.

Going to base 12 would also fit with going back to inches, shillings, ...

#### Dogtrousers

##### Kilometre nibbler
And we have the Italians (Leonardo de Pisa) <- {Indians,Muslims} to thank for the base 10 decimal notation, otherwise we'd all still be using Roman numerals.

Going to base 12 would also fit with going back to inches, shillings, ...
But to be fair to Roman numberals they are base 10 but they are a bit rubbish, as they lack zero.

#### MartinQ

##### Veteran
But to be fair to Roman numberals they are base 10 but they are a bit rubbish, as they lack zero.
It could equally be argued that they're base 5 but agreed about the lack of zero and the need for an ever increasing number of letters as the numbers grow. The real problem was multiplying and dividing with them. Even so it took a long time for decimal-place value to take over in Europe.

From memory, the Babylonian numbers were similar, going up to 12 then going up to 60 as 5*12. However my cuneiform isn't what it used to be.

#### the_mikey

##### Legendary Member
50,000 km a month is a lot

That's 50Mm, know your metric prefixes!
I haven't ridden 50µm today, too cold.

#### figbat

##### Slippery scientist
That's 50Mm, know your metric prefixes!
I haven't ridden 50µm today, too cold.
That gets me to another thing - in metric we like to have multiples of a thousand for up and down the scale, but in imperial we have fractions like 16ths, 32nds and 64ths... and “thou”. Make yer mind up!

#### figbat

##### Slippery scientist
I rode 50,000,000,000µm this afternoon

PS: aren't they suffixes
No, definitely a prefix... although I would have gone for “suffices”.

#### the_mikey

##### Legendary Member
I rode 50,000,000,000µm this afternoon

PS: aren't they suffixes
As they appear on paper they do look like suffixes, but they're known as prefixes!

#### Mark pallister

##### Senior Member
Because imperial measurements are a really poor way of measuring distance. Decimalisation is so much clearer and easier to break down.

We've pretty much done away with feet and inches in manufacturing in favour of millimetres and the only reasons people persist with miles is because of history and the fact it's still how our speed limits and road signs are shown.
And it’s what’s shown on your car speedometer

#### figbat

##### Slippery scientist
And it’s what’s shown on your car speedometer
UK cars must also be able to display km/h, although continental European cars don’t have to be able to display mph. Maybe Brexit will fix this demonstrably discriminative issue.

#### Dogtrousers

##### Kilometre nibbler
I think I may change to parsecs.

#### Ming the Merciless

##### Formerly YukonBoy
That's 50Mm, know your metric prefixes!
I haven't ridden 50µm today, too cold.
Indeed it is and if you refer back you will see that they did say 50k and did not indicate units km, m, cm, miles or otherwise In a thread about km we must assume 50,000 km!

#### RichardB

##### Slightly retro
Just shows how foresighed Leonardo de Pisa was when he described the Fibonacci sequence 800 years ago. The next/previous number is your km/mile equivalent, so
5 - 8 - 13 - 21 - 34 - 55 - 89 ...
I had noticed this, too. It's not exact, but near enough for approximation purposes. I've wondered for a long time if this is just a coincidence, or if there is a deeper connection between the two. Probably coincidence. Incidentally, there is a book called 'Nature's Numbers' by Ian Stewart which has a fascinating chapter on the Fibonacci sequence, relating it to the Golden Mean/Golden Section, the design of flower heads, snail shells and all sorts. Out of print now, but worth tracking down a copy if this kind of thing floats your boat.

Being brought up on Imperial units (ho ho), my mental arithmetic is quite good, so for miles/km I just multiply or divide by 1.6. Easy and near enough for most purposes.

#### RichardB

##### Slightly retro
AND where it is a metal posts with the pointers held on with extra large jubilee clips they tend to point in the opposite direction (wind small boys turns them).
FTFY. Been there, done that, watched the confusion.