Wiktionary
vb. (present participle of add up English)
Usage examples of "adding up".
Once I knew where to start, it wasn't hard to start adding up the numbers.
I remember doing the math, adding up the hours, and realizing that she must have been traveling con.
Jamil had been putting this off, because he was certain he would be in for a barrage of excuses and evasions, all adding up to the fact that Raoul had, and after much work, obtained an autographed vid of Rusty Love.
Ander was still regarding him with that expression of pleasant inquiry that was somehow adding up to an aggressive challenge in Bias's head.
Before him on his counter lay a sheet of paper on which he was adding up imaginary columns of figures.
Something was not adding up because I wasn't hearing Humanis Policlub rhetoric coming at me.