I have seen some scales that convert units and some that don't
first is convert
the scale converts from smaller to bigger
?:1in
6ft/8in=0.75ft/1
scale is 0.75ft:1in
other one doesn't convert dimentions
6ft=6*12in=72in
72in:8in
9:1
that is most ilkely what teacher is looking for
scale is 9:1
72in:8in