tally vs add up

tally is a noun but add up is not a noun.

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

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

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

tally (noun)	add up (noun)
the act of counting; reciting numbers in ascending order
a score in baseball made by a runner touching all four bases safely
a bill for an amount due

tally (verb)	add up (verb)
determine the sum of	determine the sum of
keep score, as in games	be reasonable or logical or comprehensible
gain points in a game	to measure up to in kind or quality
be compatible, similar or consistent; coincide in their characteristics	add up in number or quantity