The Kohner Easy Adder

The Easy Adder by Kohner is a toy adding machine from the mid 1960s. It has a single dial like an old rotary phone with which you can add a digit to the total. It can also subtract.
Stephen Freeborn has a nice video of this machine: • Kohner Easy Adder Addi...
For more information about this and other machines in my collection, please visit my website:
www.jaapsch.net/mechcalc/
0:00 Introduction
0:16 Addition
0:46 Subtraction
1:21 Clearing
2:27 Mechanism
4:51 Outro

[@guldilo]

Thank you! Beautiful toy!

[@rubberswan]

I have one of those in the opposite colour way - the red bits are yellow, and the yellow bits are red.

[@jaapsch2]

I've also seen pictures of a blue one, but it seems the red ones are by far the most common.