Extended Strong's Greek Lexicon (Abbott-Smith based)
to calculate
Usage: ψηφίζω (ψῆφος), [in LXX: 3Ki.3:8 8:5 A (סָפַר ni..) * ;] to count (prop., with pebbles), reckon, calculate: τ. δαπάνην, Luk.14:28; τ. ἀριθμόν (i.e. calculate the number's meaning), Rev.13:18 (in cl. chiefly mid., to vote by casting a pebble; cf. συγ-κατα-, συμ-φηφίζω).† (AS)