I recently made a simplified version of a damage display system. This assumes you review your programming, or at least test it. And do not need and fault-checks. (If you do need those, I would suggest Flick's F_Damage system.)

http://www.byond.com/developer/Leur/l.atkn

Breakdown:

l_disp(trg,n,col)
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trg = Target (As mob) to display the attack above.
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n = The number to display.
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col = The color you want the number to display as. (If left blank it will stay white.)