Abstract
Scientific and technological developments rely strongly on mathematical skills. However, mensuration is a challenging topic in school mathematics, leading to poor performance by many students. Various factors are responsible for the unsatisfactory performance, including inappropriate teaching methods where students passively absorb knowledge transmitted through reading and explanations of textbook contents. Thus, this study examined how a cooperative learning method affected students' performance in mensuration. A quasi-experimental research design was used in the study. The sample comprised two intact classes of 80 students assigned to experimental and control groups selected from one senior secondary school in Ogun State. Data were collected using an adopted standardised mensuration achievement test (MAT), which takes an analytical approach that includes problem-solving, geometric reasoning, formula application, and conceptual comprehension. The results showed a statistically significant difference between the mean score (M=11.18, SD=3.09) of students taught mensuration using the cooperative learning method and the mean score (M=7.66, SD=3.32) of students taught mensuration without using the learning method of teaching (t (78)=9.50, p=0.00). Also, the mean score varied statistically significantly (M=7.66, SD=2.63) of male students taught mensuration using the cooperative learning method and the mean score (M=8.73, SD=3.08) of female students taught mensuration without using the learning method of teaching (t (78) = 6.58, p=0.00). Therefore, cooperative learning in mathematics classrooms fosters students' ability to create and achieve learning objectives.