The Collaborative International Dictionary
Arithmetically \Ar`ith*met"ic*al*ly\, adv. Conformably to the principles or methods of arithmetic.
Wiktionary
adv. In an arithmetic manner; respecting arithmetic.
WordNet
adv. with respect to arithmetic; "this problem is arithmetically easy"
Usage examples of "arithmetically".
Godel numbers of the wfifs are arithmetically related to each other in just the right way.
If the timing was somehow off, if the wormhole was growing geometrically instead of arithmetically, then the Furies would arrive before the reinforcements.
He believed that all measurements and constants might be arithmetically derived from a single number, the cipher of the Preservers which could unlock the secrets of the world they had made, and much else.
Consider, too, for example, the opposition to an arithmetically convenient system of measurement in certain quarters on Earth, apparently because of the unwillingness to surrender the techniques of tradition, so painfully acquired so long ago.