Samuel J, Nio TH, Simbolon K. The Effect of Numbered Head Together Learning Model Assisted by Learner Worksheets on Mathematical Problem-solving Ability. EduMatSains [Internet]. 2025 Oct. 31 [cited 2026 Apr. 28];10(2):1-14. Available from: https://ejournal.uki.ac.id/index.php/edumatsains/article/view/7011