PENGARUH MODEL PEMBELAJARAN OPEN ENDED TERHADAP KEMAMPUAN PENALARAN MATEMATIKA DI KELAS TINGGI SEKOLAH DASAR - Habibah, Hainun (Department of Madrasah Ibtidaiyah Teacher Education, Faculty of Tarbiyah, Universitas Ibn Khaldun Bogor In Collaboration with Perkumpulan Dosen Pendidikan Guru Madrasah Ibtidaiyah (PD PGMI) Indonesia, 2021)