Uploaded September 2022 | Updated September 2026, 2 hours ago

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The Addo-X 341 is an adding machine made in Sweden in the 1950s. My version has a carriage for feeding paper sheets, but most just had a simple paper roll.

For more information on this and other machines in my collection, please visit my website:
jaapsch.net/mechcalc

0:00 Introduction
0:25 History
1:35 Entering numbers
2:00 Addition
2:16 Subtraction
2:50 Subtotals and totals
4:20 Symmetric keyboard
4:45 Multiplication
5:55 Step-O-Matic
6:54 Non-Add
7:14 Carriage
8:44 Addo-X 351
9:33 Ink ribbon
9:49 Power cord
11:06 Outro