Looking at the arrangement rules horizontally: each line goes from left to right, which line is currently in, from the number 1 to the current line number, respectively multiplied by the current line number, and then increased from left to right. Looking at the arrangement law vertically: each column is multiplied by the current column number from top to bottom, and the number is increased from top to bottom.

multiplication table

The multiplication table is a formula for primary school students, starting from "11" and ending at "998 1", but in ancient times it was the other way around, starting at "998 1" and ending at "224". Because the first two words of the formula are "99", people call it "Xiao 99" for short. It was only in the 13 and 14 centuries that it turned into the present situation.

Multiplication and carry system has existed in ancient Babylon for a long time, but the operation process is not as simple and fast as formula 99, and it is not easy to remember. China used the "99 formula" earlier. Sentences such as "3927", "684 18", "483 12" and "6636" can be found in books such as Xunzi, Guanzi, Huainanzi and Warring States Policy. It can be seen that as early as the Spring and Autumn Period and the Warring States Period, 99 multiplication songs became popular.