"Slide rule", invented in the 1600s.
Used until the 1970s. Any university science student owned a slide rule, until approximately 1980. (supplanted by calculators)
In class, I illustrated 2+3 with linear rulers on an overhead.
Then, gave a
brief explanation of logarithmic scale; illustrated 2*3 with logarithmic rulers
A fair sophistication with numbers is required to use a slide rule (mostly because of details which we didn't get in to in the class). But it still tells you something you didn't know.
You do lose some understanding of numbers in using a calculator.