HBO MAXSERIESMOVIESNEW & LAST CHANCESCHEDULEMoreDocumentariesSpecialsSportsPodcastsSIGN INGET HBOMAXHBO MAXSERIESMOVIESNEW & LAST CHANCESCHEDULEMoreDocumentariesSpecialsSportsPodcastsSIGN INGET HBOMAXSIGN INStream all of HBO plus more TV, movies, and Max Originals at no additional cost.SIGN INHBO MaxThe Number on Great-Grandpa's Arm TV-PG | documentary | 19 MIN | 2018 WATCH NOWHBO MaxWatch on HBOAn American boy and his great-grandfather, an Auschwitz survivor, share a conversation in this inspirational film.