This adding machine came out in the early 1970s at a cost around $50 (About $354.44 with inflation). This calculator prints everything onto 2 1/4 inch paper roll. Made by Kawasaki in Japan.
How to use the calculator from a YouTube comment:
Youtube user: tvdan1043
The X key was basically a lock so it wouldn’t clear your entry after adding or subtracting so you could add/subtract the same value multiple times without re-entering it. Need to know what 1.75 times 5 is? Punch in 175, hit the X, then hit + five times in a row. Clear the entry and then hit S or T to get a result of 8.75. It worked mechanically just like the Shift Lock key on a manual typewriter.
They also added:
My dad had one of these adding machines. There was always a metallic smell in the air when he used it for more than a few minutes at a time.
Photos of the Manual:
Photos from scanner are 1200 DPI Resolution which means they are HUGE Files. (1.30GB just in 8 images)
You can download the ZIP of the full scan resolutions here WARNING 1.3GB Download
Source:
https://americanhistory.si.edu/collections/search/object/nmah_690103
https://www.usinflationcalculator.com/
https://www.youtube.com/watch?v=uVWQQhjB0kM