ria Irawati and Sri Wahyuni 2022. Numbered Heads Together (Nht) Cooperative Learning Model on Students’ Mathematic Problem Solving Ability Study on Class ViII Students of Golden Star Informatics SMP. Mathematics Research and Education Journal. 6, 2 (Oct. 2022). DOI:https://doi.org/10.25299/mrej.2022.vol6(2).10145.