EntityQ10419540· pop 5· linked from 11 articlesmental abacusSign in to savesystem where users mentally visualize an abacus to do calculationsConnectionsmotorsportEntityFIFA World CupConceptInternational Standard Book NumberEntityRichard FeynmanEntityFormula OneConceptabacusEntityThe GuardianEntitydigital object identifierEntitycue sportsEntityOCLC, Inc.EntityFIFA Club World CupEntityQ180686EntityDavis CupEntityFIFA Women's World CupEntityWorld Athletics ChampionshipsEntityelectroencephalographyEntitybibcodeEntityRugby World CupEntityCricket World CupConceptOlympic sportEntityCategoriesAbacusCompetitionsGames of mental skillMathematics competitionsMental calculation