What scale is 4mm as a ratio?

[JeffP]

But before that it was four grains of barley placed end to end, twelve poppy seeds, ditto, or one twelfth of one foot.

Your new "definition" isn't.

It's an equivalence.

And our inch predates their system😄

[Il Grifone]

2.54cm is the actual definition of an inch since 1959.

https://www.britannica.com/science/inch

https://www.vedantu.com/physics/inch

 

Earlier definitions in the above links are rather open to error....

Spot the arithmetical error in the second link!

 

 

 

Edited December 25, 2022 by Il Grifone
Error in units.

[cctransuk]

Just now, Il Grifone said:

2.54mm is the actual definition of an inch since 1959.

https://www.britannica.com/science/inch

https://www.vedantu.com/physics/inch

 

Earlier definitions in the above links are rather open to error....

Spot the arithmetical error in the second link!

 

 

 

 

mm. ? Surely cm. ?

 

CJI.

[Darius43]

30 minutes ago, cctransuk said:

 

mm. ? Surely cm. ?

 

CJI.

Thats “shrinkflation” for you…

 

Cheers

 

Darius

[MJI]

I had to add conversion to from inches to our software.

 

An inch is defined as 25.4mm. It used to be 25.42 many years ago, but the inch does not have an accurate base unlike the metre.

 

So 4mm to the foot is 76.2 exactly.

[57xx]

On 23/12/2022 at 13:29, Steamport Southport said:

 

See? If you ditch the Metric system you could do away with all those pointless decimal points.

 

The French have a lot to answer for.....

 

 

In favour of pointless fractions?

 

[Il Grifone]

Thousandths of an inch?????

 

Decimals are a separate argument from Metric. You can just as easily talk about a quarter of a litre as 250 cc sorry ml.

Tens are easy to divide/multiply by anyway. Try using fractions on a calculator!

 

Edited December 27, 2022 by Il Grifone