zulhendrik, Ambiyar, Ishak Aziz. THE ABILITY TO UNDERSTAND MATHEMATICAL CONCEPT OF STUDENTS OF CLASS VII SMPN 3 PEKANBARU THROUGH COOPERATIVE LEARNING MODEL TYPE OF GROUP INVESTIGATION. IJHESS [Internet]. 2021 Oct. 27 [cited 2025 Oct. 9];1(2). Available from: https://ijhess.com/index.php/ijhess/article/view/45