“PENINGKATAN PRESTASI BELAJAR MATEMATIKA MATERI PERKALIAN MELALUI MEDIA ABAKUS BAGI SISWA TUNANETRA ”, orthopaedagogia, vol. 1, no. 01, pp. 27–35, Feb. 2013, Accessed: Oct. 30, 2024. [Online]. Available: https://journal.uns.ac.id/index.php/orthopaedagogia/article/view/1167