dimension problem

[robpage]

This is weird.  I'm dimensioning a drawing and Fusion is telling me that 9 1/4"+ 9 1/4" = 18 1/4".  What's weirder, using the measure tool in my model I'm getting 18.333".  (The measure tool is also telling me that the 18 3/4" dimension on the left is 18.666 in the model.)  I don't know what to trust.  Not sure what I'm doing wrong.  It must be a rounding error?  When I switch to decimal it tells me 9.17 + 9.17 = 18.33...close enough!  So what's right?

EDIT:  I redid this in metric and the numbers all add up.

[davebYYPCU]

So when did 9 1/4, ever equal 9.17, 

Must be those new school ciriculums, cause it will always be 9.25 at my place.

[robpage]

Just answered my own question.  Found the "dimension precision" dialogs.  Brilliant program but wow, deep!