Is there more to the question?
The only thing I can think of to do is make it a ratio.
6" : 10'
The first thing to do is make the two the same, so I will change the 10' into inches. 10' = 120"
Then simplify the ratio 6" : 120"
Divde both sides by 6: 1" : 20"
Edited to correct a silly mistake.