When i was doing my Calc testing they wouldnt let us use the fancy Calcs that did it all for you... you had to use the simpler ones...
We didn't have them to use...they existed, but were prohibitively expensive. I saw my old slide rule in my parents' basement a few years ago, and couldn't remember how to use it.
Heck I had to use a slide rule. Thank God for calculators.
My daughter took calc in college and the college policy was NO CALCULATORS at all.
So, she brought her slide rule and asked if she could use that.
After the stunned silence that anyone knew how to use it in the first place, mush less had one, they said sure. The rules didn’t say anything about slide rules.
It helped her get through the basic multiplication part easier.
Just as an aside, she can do plenty complicated math in her head. I adamantly refused to allow them calculators in homeschool until they reached about second year algebra and could prove to me that they could multiply in their heads. Then is was just a matter of convenience, to speed things up.