Home›Abacus›mental abacus🌐EnglishEnglishItalianoРусский中文EntityQ10419540· pop 5· linked from 11 articlesmental abacusAlso known as abacus systemsystem where users mentally visualize an abacus to do calculationsWikidata factsImageAlbertoCotoAbaco.jpgvia Wikidata · CC0Available in 5 languages中文РусскийGreeksimplevia Wikidata sitelinks · CC0ConnectionsmotorsportEntityFIFA World CupConceptCategoriesAbacusCompetitionsGames of mental skillMathematics competitionsMental calculation