Before the abacus, the 2-bit calculator and definitely, our lack of mathematical skills, there was...the Antikythera mechanism.
It may look like a algae-smothered sewage knob, but the mechanism on your right was used by the Greeks to calculate astronomical positions - somehow at least. We mean look at it, it's apparently only the main fragment of the whole structure, but the only thing to calculate is how exactly did they use the damn thing. However,scientists have even found out more possible uses for it, as the device supposedly tracked the four-year cycles of the Olympiad. Let's bask in some geekness from a NYTimes report:
"Only now, applying high-resolution imaging systems and three-dimensional X-ray tomography, have experts been able to decipher inscriptions and reconstruct functions of the bronze gears on the mechanism. The latest research has revealed details of dials on the instrument's back side, including the names of all 12 months of an ancient calendar."