Apparently similarly mechanically powered displays involving cams to actuate number segments were pretty popular back in the day. Here's a YouTube video I came across one day a while back about one: https://youtu.be/TANe2d0VTGQ?si=unBJmfzs6A_7PWkM
I got irrationally angry that the first digit in the clock could only be 1 or nothing until I saw the actual mechanism and realized that they did that to probably save on material.
Watching it, my first thought was if it could also be used as s display for a large calculator? Guessing the computation part would require electronics, but then again, there used to be geared tabletop calculators.
They could be made fairly small. The Curta calculator was hand held. Unfortunately, they are very expensive now, but there is a simulator online if you want to play with one.