First portable electronic calculator made by Sharp. Model EL-8. Made in Japan. Circa: 1970s.

First portable electronic calculator made by Sharp. Model EL-8. Made in Japan. Circa: 1970s.

Vintage Rockwell Calculator 10R. (The buttons look like they were made of caramel).

This Panasonic calculator has a very futuristic feel to it. Come to think of it, it looks a little like iPhone. Circa: 1970s.

This Panasonic calculator has a very futuristic feel to it. Come to think of it, it looks a little like iPhone. Circa: 1970s.

Calculator Hybrid? Old and new technology side by side. Calculator has 8 digits; Abacus uses 13 decimals.

Calculator Hybrid? Old and new technology side by side. Calculator has 8 digits; Abacus uses 13 decimals.

Vintage Casio Personal-Mini Calculator. Circa: 1970s.

Vintage Casio Personal-Mini Calculator. Circa: 1970s.

Vintage Commodore C-112 Tabletop Calculator. Circa: 1970s.

Vintage Commodore C-112 Tabletop Calculator. Circa: 1970s.