add together vs reckon

add together and reckon both are verbs.

Word	Noun	Adjective	Verb	Adverb
add together	No	No	Yes	No
reckon	No	No	Yes	No

As verbs, reckon is a hypernym of add together; that is, reckon is a word with a broader meaning than add together:

Other hypernyms of add together include calculate, cipher, compute, cypher, figure, work out.

add together (verb)	reckon (verb)
make an addition by combining numbers	deem to be
determine the sum of	make a mathematical calculation or computation
	expect, believe, or suppose
	judge to be probable
	have faith or confidence in
	take account of