approximation vs figuring

approximation and figuring both are nouns.

Word	Noun	Adjective	Verb	Adverb
approximation	Yes	No	No	No
figuring	Yes	No	No	No

As nouns, figuring is a hypernym of approximation; that is, figuring is a word with a broader meaning than approximation:

Other hypernyms of approximation include calculation, computation, reckoning.

approximation (noun)	figuring (noun)
the act of bringing near or bringing together especially the cut edges of tissue	problem solving that involves numbers or quantities
the quality of coming near to identity (especially close in quantity)
an approximate calculation of quantity or degree or worth
an imprecise or incomplete account