This study aims to find out whether the Numbered Head Together (NHT) type cooperative learning model has an effect on students' mathematical problem-solving ability at SMP Negeri 5 Jambi City. This research was conducted at SMP Negeri 5 Jambi City for the 2023/2024 school year. This type of research is quantitative research. This study is an experimental research with a Posttest-Only Control Design. The population is all grade VIII students of SMP Negeri 5 Jambi City. Sample withdrawal was carried out using the Cluster Random Sampling technique. The researcher randomly took two selected classes, class VIII B as the experimental class and class VIII C as the control class. The instrument used is a final test in the form of essay questions to see students' mathematical problem-solving skills. The test data was analyzed using a one-party t-test, namely the right-hand test assisted by SPSS version 29.0. The results showed that the average score of mathematical problem-solving ability of students in the experimental class was 63.33 and the average score of mathematical problem-solving students in the control class was 41.44. Meanwhile, based on the results of the analysis of the independent sample t-test with a significant level of 5% (α = 0.05), a significant value (1-talled) of 0.0005 was obtained, so it can be seen that 0.0005 < 0.05. Based on the results of this study, it can be concluded that the Numbered Head Together (NHT) type cooperative learning model has an effect on students' mathematical problem-solving ability.
Hakim et al. (Sun,) studied this question.