Last year I picked up a bamboo Hemi and worked through the (70yo!) workbook. The trigonometric scales are cool. Making a single slide to find all the sides of a triangle is surprisingly satisfying. It got me to realize that, sliderules with the right scales can solve the roots of any 3-variable equation. I guess this is why there was a proliferation of industry-specific sliderules back in the day.
More generally, aren't simple, well-engineered analog tools so satisfying?