The ancient Incas used a mysterious calculating device called the Yupana, which was used for mathematical calculations and urban planning. Very little is known about the Yupana due to its rarity and lack of historical literature. There are only a few surviving Yupanas, with examples found in various museums around the world. The Yupana was versatile, capable of performing addition, subtraction, multiplication, and division. Scholars have proposed various hypotheses about how the Incas used the Yupana, but its exact function remains unknown. The Yupana is a fascinating ancient artifact that continues to mystify researchers to this day.
https://cacm.acm.org/blogcacm/technical-marvels-part-3-the-yupana/