Who invented the multiplying by lines method?

Answer 1

The method of multiplying by lines, also known as the "line multiplication" or "stick multiplication," is often attributed to ancient civilizations, particularly the Egyptians and the Chinese. However, it was popularized in Europe by the mathematician Leonardo of Pisa, known as Fibonacci, in the early 13th century. He introduced it in his seminal work, "Liber Abaci," which helped spread the use of Hindu-Arabic numerals in Europe. The method itself, however, has roots that predate Fibonacci's work.