Ancient Egyptian paper books recorded a multiplication-multiplication. Its basic algorithm is to double the calculation first, and then combine different multiples to complete the calculation. The specific process is as follows:

The multiplication operation in ancient Egypt does not need a lot of memory, just know two multiplication tables.

For a simple example, to multiply "12× 16", they will start with 1 and 12, and then they will multiply the numbers in each column by 2 (12 and12× 2). 2×2 and 24×2, and so on) until the number 16 is multiplied, and the result is 192.

Multiplication:

Multiplication, also known as multiplication and division, is a fast multiplication. It refers to the multiplication of multiplicand directly using multiples of 1, 2,5 without using formula 99. It is a simple multiplication operation between ancient people in China.

Ancient books were first found in Jason Wu's Nine Chapters Algorithm Analogy in Ming Dynasty (1450). After modern improvement, on the basis of mastering 2-5 mental calculations, 3, 4, 6, 7, 8 and 9 were converted into 1, 2 and 5 calculations.

Baidu encyclopedia-multiplication

Baidu Encyclopedia-Ancient Egyptian Mathematics