Toán was born in 1857. Toán's father was Nhẫn and his mother was Trinh Đỗ. His paternal grandparents were Thụy and Canh Nghiêm. He had four brothers and five sisters, named Lư, Diệp, Thu, Bướm, Hanh, Ninh, Tri, Minh and Ty. He died due to giỗ 19/12 âm lịch.