Byrd:

You are probably correct, but what I have demonstrated uses decimals for the convenience of those who wish to confirm the measures.
Eg.: If I gave two measures of a rectangle 5 1/12 by 4 1/4 then it is a pencil and paper operation or the trouble of finding a common denominator then expanding, adding and dividing again.
Much easier if I give the reader 5.083 x 4.250

I don't understand your statement re: "finished ones", could you expand a little further for me please.

Thanks and the best.
Clive