exactly.
a 1/10 scale means that 1cm on paper is 10cm in reality. therefore 10cm on paper is 100cm (or 1m) in reality.
Usually, when dealing with scales, we tend to use similar units :
we’ll say 1/10 for 1cm = 10cm or 1m = 10m but we won’t say 10cm = 1m even though it’s the same scale. that would be a bit confusing.
a 1/10 scale means the drawing is 10 times smaller than reality.
a 10/1 scale means that the drawing is 10 times bigger than reality, that’s why we use the same unit on both sides, to avoid mistakes.
However, because not everyone got trained about scales, Layout features a very smart scaling system where you can create your own by using your own values.
(this is the mac interface, but it works the same on PC)
I can have two different units, layout will do the math :
(because 1m is 100cm)