Lelawarna, L. 2018. Effort Increasing Learning Result Of Communication Operations Calculating Methods Using Napier Bone Students Class Students In Basic Schools 12 Tebat Karai. Jurnal PGSD: Jurnal Ilmiah Pendidikan Guru Sekolah Dasar. 11, 2 (Dec. 2018), 112–119. DOI:https://doi.org/10.33369/pgsd.11.2.112-119.