Adding machine (10)
I believe the answer is:
calculator
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">adding machine</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for calculator that I've seen before include "Sum-doer's aid" , "Ready reckoner" , "See 12" , "Adding machine" , "this should provide some answers" .)