sentences:  The school takes its pupils mainly from the Sanderstead, Selsdon, Purley, Kenley, New Addington and South Croydon areas, and specialises in science.Riddlesdown is the largest school in Croydon in terms of pupil numbers.In September 2009, the school's name changed from Riddlesdown High School to Riddlesdown Collegiate, featuring six colleges; four of which will hold a mixture of years 7–11, a Creative Performing Arts college and a Sixth Form college.