This image was acquired from
wikimedia. It was marked as Public Domain or CC0 and is free to use. To verify, go to the source and check the information there.
Taijitu abacus Ridai Museum of Modern Science Tokyo DSC. en Exhibit in the Ridai Museum of Modern Science Tokyo University of Science Kagurazaka campus Kagurazaka Shinjukuku Tokyo own Daderot other versions cczero Abaci in the Ridai Museum of Modern Science Taijitu
Page 2023 Free-images.com. All images are Public Domain