The Tchokwe people lived on the African continent, in Mozambique and Angola. The sona belong to their cultural tradition. The sona are drawings made in the sand by older members of the tribe to tell stories, essential in the youngests' formation. In this article, we show a relationship between the sona and the greatest common divisor (GCD) of two integers. We recognize in the sona a rich mathematical content that allows the teaching of the GCD concept and illustrates the strength and cultural sophistication of the Tchokwe people and their mathematics. It can be a playful way of dealing with a fundamental concept with lower-secondary education students.