# Abacus

Shows how to use the open-end abacus. Discusses the history of the decimal number system and principles of its use, such as grouping in addition, regrouping in subtraction and comparison of number values. To license this film and get a higher quality version for broadcast/film purposes, contact A/V Geeks LLC.

- Kind: Film
- Year: 1958
- By: Avis Films
- Genres: Industrial and advertising
- Archive: [Internet Archive](https://archive.org/details/Abacus_201511)
- Licence or status: none stated by the archive
- Who can watch: Tweens profiles and older (the archive gives no rating; placed by Invisible Network from its collection and subjects)

[Watch now](https://invisiblenetwork.ai/watch/archive/ia/Abacus_201511?play=1)