What do you use a architecht scale for?
A scale is like a ruler which helps architects and builders read
plans and convert the measurements on paper to the measurements of
the real building.
Because we can't make architectural drawings as large as real
life, we scale them down. Some commonly used scales are 1:100,
1:250, 1:50 etc. The scale is determined by how big the building is
and how much detail the plans need to show so that you can see
what's going on.
With a 1:100 scale drawing, every unit on the page is equal to
100 units in real life. So the 1:100 part of the scale ruler shows
"1m" where on a regular ruler it would say "1cm".