This research has purpose to improve the ability of student in studyin mathematics by applying cooperative learning method calledNumbered Heads Together (NHT)in fourth grade SD Negeri 001 Teluk Pinang. NHT is a cooperative learningmethod, in which students are placed into groups of 4-5 people and each group are numbered 1-5. The research was conducted in April to May 2014. The subject of this r…