13:15NumbertimeAddition and SubtractionAddition and Subtraction: Patterns of subtractionBBC Two Duration: 15 minutes Wed 27th Apr 2005, 13:15 on BBC Two Wales (Analogue)Addition and subtraction using animations, songs and sketches. Shows the relationship between practical problem solving and written calculations.BrandNumbertimeSeriesNumbertime: Addition and Subtraction Source: BBC Online