Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
nŭmĕrātĭo, ōnis, f. [numero], a counting out, paying, payment (post-Aug.): ubi numeratio exigetur, Col. 1, 8, 13; 11, 1, 24: ab isto fiet numeratio, Sen. Ep. 18, 4; 26, 8: numeratio pecuniae rei, non litterarum, facit obligationem, Gai. Inst. 3, 131 sq.