Quite often I get sent a 2D Drawing (DXF or DWG) from a customer and I open it in DraftSight.  If I want to determine a dimension that they haven't included on the drawing, I typically just add my own.  If the drawing is scaled, I have to multiply the dimension by the scaling factor to get the actual value.

For example, If the scale of the drawing is 1:10, and I measure 200 mm, I know that actually means 2000 mm.

I have been given a drawing that says the scale is 1:12.5, but when I place an identical measurement next to one indicated, it doesn't match.  For example, the dimension already on the drawing (in blue) as 2000 mm, actually measures as 156.0000:

Part of the drawing, as sent to me

After adding my own dimension to double-check the scale

However, 2000 divided by 156 is something like 1:12.82051282..... not 1:12.5.

I feel like I am missing something really obvious here in DraftSight as far as how dimensions are made.  Or, is it just that the person who made this drawing potentially originally had it at 1:12.5, then resized it a little at some later point, which screwed everything up?

Does anyone else ever have this same problem?  If so, what is your workaround?

Thanks in advance,

-Iain