Prepare a piece of cardboard, draw the same grid on it (according to the style of multiplication formula), first fill in the mouth of 1 from the leftmost grid, fill it in the same way in turn, and finally fill in the mouth of 9, and then draw a border around the whole table, and a simple multiplication table is completed.

increase

The multiplication formula is the basic calculation rule of multiplication, division and square root in ancient China. Used for more than two thousand years, the multiplication table is also the basic skill of elementary school arithmetic.

The ancient multiplication formula is from top to bottom, from "998 1" to "one to one", which is contrary to the order of use. Therefore, the ancients used the word "99" at the beginning of the multiplication formula as the name of this formula, also known as "99 table", "99 song" and "99 multiplication table".

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, "Jiujiucheng Song" has become popular.

Knowledge expansion:

Jiujiubiao, also known as Jiujiusong and Jiuyinsong, is the basic calculation rule of multiplication and division in ancient China, which has been more than two thousand years since. Pupils and some school-age children can recite it. But Europe didn't know this simple multiplication table until the beginning of 13 century.

The ancient western civilizations Greece and Babylon also invented the multiplication table, but it is more complicated than the 999 table. There are more than 1700 Greek multiplication tables invented by Babylon, and they are not complete enough. Because they worked hard to calculate multiplication and division before 13 century, people who can divide large numbers will be considered as experts in mathematics.

/kloc-At the beginning of the third century, the eastern calculation method was introduced to Europe through Arabs, and Europeans discovered its convenience, so they learned this new method. At that time, the topic of multiplying two numbers by a new method was the textbook of the university at that time.