Neat Video!
Okay - scale is the measurement used in drawings to proportionally represent the item that is being drawn. I hope this is right! I know what it is, but have never had to describe it before.
Bizarrely enough, the U.S. still insists upon using the Imperial measuring system - inches, feet, yards, miles etc. Britain now officially uses the metric system (although the imperial system seeps through in everyday life) and anyo other country I've been to in Europe or Asia uses the metric system. We're the odd country out. Change is hard I guess.