Marcin Wichary on Twitter: "Mechanical Olivetti Summa 15 calculator from 1949. (Source: https://t.co/TYtaB9L9Me) https://t.co/59UNjjj9ym" / Twitter
![Sold at Auction: Olivetti Summa 15 calculator, with design signed by Natale Capellaro and Marcello Nizzoli, Italy, approx. 1949-1956 Sold at Auction: Olivetti Summa 15 calculator, with design signed by Natale Capellaro and Marcello Nizzoli, Italy, approx. 1949-1956](https://image.invaluable.com/housePhotos/Artmark/00/743600/H21369-L323232107.jpg)
Sold at Auction: Olivetti Summa 15 calculator, with design signed by Natale Capellaro and Marcello Nizzoli, Italy, approx. 1949-1956
![Sold at Auction: Giovanni (1946) Pintori, Miscellaneous posters.- Pintori (Giovanni) Olivetti Summa 15, 1955; and 9 others (10) Sold at Auction: Giovanni (1946) Pintori, Miscellaneous posters.- Pintori (Giovanni) Olivetti Summa 15, 1955; and 9 others (10)](https://image.invaluable.com/housePhotos/Forum-Auctions/80/682080/H20198-L223033095.jpg)
Sold at Auction: Giovanni (1946) Pintori, Miscellaneous posters.- Pintori (Giovanni) Olivetti Summa 15, 1955; and 9 others (10)
![Modem Times on Twitter: "The 1949 Olivetti Summa 15 manual calculator. This version has two additional digit keys (10 and 11) to allow it to calculate pre-decimal British currency - 12 pennies Modem Times on Twitter: "The 1949 Olivetti Summa 15 manual calculator. This version has two additional digit keys (10 and 11) to allow it to calculate pre-decimal British currency - 12 pennies](https://pbs.twimg.com/media/D3JW3EZWAAEWaCZ.jpg)
Modem Times on Twitter: "The 1949 Olivetti Summa 15 manual calculator. This version has two additional digit keys (10 and 11) to allow it to calculate pre-decimal British currency - 12 pennies
![Olivetti Summa 15, progetto Natale Capellaro, design Marcello Nizzoli, 1949 - Museo dell'Informatica Funzionante Olivetti Summa 15, progetto Natale Capellaro, design Marcello Nizzoli, 1949 - Museo dell'Informatica Funzionante](https://i0.wp.com/museo.freaknet.org/wp-content/uploads/2015/08/Olivetti-Summa-15-progetto-Natale-Capellaro-design-Marcello-Nizzoli-1949.jpg?ssl=1)