rpn for for the win I guess ;-). I actually didn't get to try my first linux stuff until grad school in the 80s. I wish I had saved off all my init files from then to see what they look like now.
Back in the day (Unix Seventh Edition) bc was just a front end that compiled the expression and piped it to dc. My take it is most people didn't find rpn a win, and bc was the fix.
I used bc's compiled output ("bc -c") to learn how to make dc jump through hoops.