Miscalculates (4)
I believe the answer is:
errs
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">miscalculates</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for errs that I've seen before include "Is mistaken" , "Makes mistakes" , "Goes wrong" , "Goes astray" , "Strays" .)