This action research aims to improve students’ mathematics achievement using Number Head Together in Cooperative Learning. The subjects were students of X.5 Class at SMAN 10 Pekanbaru in 2015/2016. The model was implemented in two cycles. Data were collected through mathematics test, observation sheets on learning process and questionnaire. Data were analysed through quantitative and qualitative analysis. In the first cycle, students mathematics achievement improve to 52,5%. In the second cycle, students mathematics achievement improve to 77,5%. It satisfied the criteria for successful action of this research. To sum up, it can be conclude that number head together in cooperative learning can be alternative modal that can be implemented to improve students’ mathematics achievement.
Cooperative learning, number head together, students’ mathematics achievement