fix stupid Maths mistake

combat.tex

@@ -510,7 +510,7 @@ Stacked armour can consist of both partial and complete layers, meaning a roll c
 
 	For example, a basilisk with \gls{dr} 4 might die, and then get raised from the dead by a necromancer.
 	The undead naturally have a \gls{dr} of 2, so this secondary source of damage would count for half, giving it a total \gls{dr} of 5.
-	If the mage were crazy enough to add plate armour to the basilisk, the total \gls{dr} would be $5 + \frac{4}{2} + \frac{2}{4} = 7.25$, or `7'.
+	If the mage were crazy enough to add plate armour to the basilisk, the total \gls{dr} would be $5 + \frac{4}{2} + \frac{2}{4} = 7.5$, or `8'.
 
 	Of course if this were \textit{partial} plate armour, any roll which gets 3 over the basilisk's \gls{tn} would only get the \gls{dr} of 5.
 }{}