The Curta Calculator

Here I demonstrate how to use a Curta Calculator, Type I. I also show some interesting paper items relating to the Curta, including a letter about and drawing of two Curtas joined together to form a single calculator.
For more information about the Curta and other mechanical calvulators in my collection, visit my website:
www.jaapsch.net/mechcalc/
0:00 Introduction
0:16 History
1:14 Description
1:42 Inputting
2:00 Addition
2:22 Multiplication
2:58 Subtraction
3:38 Clearing
4:25 Division
6:28 Storage
6:58 Table of square roots
7:32 Price list
8:06 Advertising leaflet
8:52 Letters
9:36 Double Curta design
11:17 Outro

[@ag6371]

This calculator looks modern although it's old. I like the Curta :)

[@gabedamien]

The reason the case opens clockwise / closes counter-clockwise is so that while closing, the case cannot accidentally twist the crank, which could partially overwrite the last op performed on the device. The crank is ratcheted so it only turns clockwise.

[@BoxofDelights]

Thank you for showing the letters and other papers. Those were really interesting! R.R.

[@Desmaad]

The emperor of them all!

[@vauxhallmark]

So beautiful!!

[@22PUZZLE22]

Wowzers. Hi Jaap! I love the Curta, but they are just a little out of my affordability range. Such a shame, as this is one of most elegant mechanical devices I've seen! Also, I must say I really love your puzzle database complete with solutions. Interesting that the case lid is threaded backwards. This resonates with me as I am mostly left-handed! It's my go-to site for reading up on rare and exotic puzzles! If you don't mind sharing, how much did this device cost?

[@jaapsch2]

I bought it in October 2010 for 400 Euro, which was a pretty good deal even then. The only thing wrong with it is that the clearing ring is cracked, and occasionally during subtraction it locks up a bit. It is the most expensive machine in my collection.

[@leinadsee]

U need to search all the time I have 3 curtas one curta type 2 y 2 type 1 and one of these cost 170 dollars and the most expensive cost 500 dollars If u search u find.