Manual Adder/Subtractor - Showa Era Item - Rare Item - Essential for those who struggle with abacuses

Manual Adder/Subtracter
?Showa era item, like something from a museum
?Rare item
?A must-have for those who struggle with abacuses

* Press the raised part on top to input numbers
* Switch between addition and subtraction with the lever on the right
* It's quite fun once you get used to it
* It was a great help to me, as I can't use an abacus