reckoning vs computation

reckoning and computation both are nouns.

Word	Noun	Adjective	Verb	Adverb
reckoning	Yes	No	No	No
computation	Yes	No	No	No

As nouns, reckoning and computation are synonyms defined as:

reckoning and computation: problem solving that involves numbers or quantities

Other synonyms of reckoning include calculation, figuring.

reckoning (noun)	computation (noun)
the act of counting; reciting numbers in ascending order	the procedure of calculating; determining something by mathematical or logical methods
problem solving that involves numbers or quantities	problem solving that involves numbers or quantities
a bill for an amount due