summate vs add up

summate and add up both are verbs.

Word	Noun	Adjective	Verb	Adverb
summate	No	No	Yes	No
add up	No	No	Yes	No

As verbs, summate and add up are synonyms defined as:

Other synonyms of summate include add, add together, sum, sum up, tally, tot, tot up, total, tote up.

summate (verb)	add up (verb)
determine the sum of	determine the sum of
form or constitute a cumulative effect	be reasonable or logical or comprehensible
	to measure up to in kind or quality
	add up in number or quantity