using your problem, we could do it like this:

16 – 8 3/8 =

[(16*8) – (8*8+3)]/8 = and you can work that out the rest of the way

or (in excruciating detail)

16 – 8 3/8 =

16-8-3/8=

8-3/8 =

7+1-3/8 =

7+8/8-3/3

7+(8-3)/8 =

7 5/8

(you should be able to do all those steps in your head quicker than you can write just the problem)

So it the question is 5 – 4 1/4

Turn it into 5-4.25

Or in the case of your question, put the 16 over 1, make the mixed into an improper and find a common demonimator

Then change 8 3/8 into an improper fraction:

8 x 8= 64. 64+3=67.

so its 67/8

so now you do 16 minus 67/8.

and subtract the fractions and then the #s