Four year old classes are for children who turn four on or before August 31 of that preschool year, and the TK class is designed for children who turn five on or before August 31. Children in the TK class could be enrolled in kindergarten according to the North Carolina Department of Public Instruction’s cut-off date, but parents choose to allow them to have an extra year of preschool. The TK class is a little more academic than the four year old classes because these children are older and have already completed a fours program. When they graduate from the TK class, they go to kindergarten and not into a first grade class.