Application of Cooperative Learning Model Based on Buying Concept to Improve the Ability of Understanding Students ‘Mathematical Concept on Statistical Lessons, Indonesia

This study discusses about how lecturer intelligence can influence their perfomance. This research is a study that uses numerical numbers and changes feed approach to quantitative methods, with descriptive research. This research is conducted in Medan city. This study examines the performance of lecturers in private universities represented by universities that have lecturers of foundations with a long category of founding universities over 10 years, namely: (1) Islamic University of North Sumatra (UISU); (2) Muhammadiyah University of North Sumatra (UMSU); (3) Muslim Nusantara University (UMN); (4) Nomensen University; (5) Indonesian Methodist University (UMI); (6) Catholic University of Santo Thomas. The result shows that                    Cognitive abilities tend to be “high” (53.33%). The average value of the overall cognitive abilities of lecturers in private universities in Medan is 81.92. Cognitive ability directly influences the performance of permanent lecturers in private universities in Medan.

Keywords: buying and selling concept, cooperative learning model, mathematical concept, understanding ability