What arithmometer is made of
A mass-produced mechanical calculator (Thomas, Odhner).
- Gear — has part. Gear wheels do the counting.
- Pinwheel with sliding teeth — has part. A wheel with retractable teeth sets a digit.
- Result register — has part. The carriage with the result.
- Crank — has part. The handle for adding and subtracting.
- Brass — is made of. Thomas’s arithmometer is brass.