Just today I gave my local agent a CSV which listed a bunch files with of human readable size units and asked it to count rows in each GB range. Sounds simple enough but it completely miscalculated, because it parsed MB as GB for some reason. In hindsight it would've be quicker just to do it in Excel or something.
That is literally what Excel is for. Why didn't you use that first of all?
I've found personally it's better to use AI to build a deterministic script for calculations like that. (anything that manipulates data should be a script not an AI).