Uploaded June 2015 | Updated September 2026, 1 hour ago

---

How to do the basic arithmetic (addition, subtraction, multiplication, division) on a Comptometer mechanical calculator.

For a look at all the features of this Super Totalizer Comptometer, see my other video:
youtu.be/I41k4q755yE

You can find more information on my site:
jaapsch.net/mechcalc