The original meaning of the word calculator was one-who-calculates. Before machines did it, scientists would get people to do the tedious work of routine number crunching. They were still in use on big government projects like the Manhattan Project, where, I have heard, certain idiot savants, people of mediocre or impaired intellect who possessed uncanny abilities in math, e.g., extracting the square-root of enormous numbers, were employed. The NYU Institute for the Study of the Ancient World is hosting a nice display of artefacts of the Ur-calculators, the scribe/engineer/mathematicians of the ancient Mesopotamian world.
The exhibit is remarkable for the evidence it presents that the Pythagorean Theorem was known to these mud scribblers 1500 years before Pythagoras himself. The scholar who edited and interpreted these pieces was adamant in his belief that much of Greek mathematics had been imported by them from elsewhere.
The header picture, from the NYTimes site, makes the tablet look like it has a very beautiful bronze-like color. It doesn’t, but it’s still pretty remarkable! It’s a list of pythagorean triples, i.e. lengths of the sides of right triangles