Lasmana, Tri Febri Marta, and Mohammad Faizal Amir. “Characteristics of Student Mental Models in Negative Round Numbers: Karakteristik Model Mental Siswa Pada Bilangan Bulat Negatif”. Proceedings of The ICECRS 8 (June 18, 2020). Accessed October 5, 2025. https://icecrs.umsida.ac.id/index.php/icecrs/article/view/435.