(1 1/6) - 5/6
1 is a whole, or 6 out of 6, or 6/6
(6/6 1/6) -5/6= 7/6-5/6=2/6=1/3
By your answer, you are subtracting 1/6 from 5/6, but you need to do the other way around as it says in the problem. Do not switch the numbers around when you subtract.
Think as you have $1 and let's say 2 cent, but you have to pay let's say 5 cents. You need to brake $1 and have 100 cents plus 2 cents =102-5=97 cents.