In-table multiplication is a simple multiplication operation of 1-9, which can be directly calculated by multiplication table. From 1× 1 to 9×9. It is the basic calculation rule of multiplication, division, square root and other operations in ancient China. The specific contents of multiplication in the table are as follows:

Intra-table division is the quotient obtained by using the above multiplication formula, and it is the inverse operation of intra-table multiplication. The details are as follows:

Extended data

The origin and characteristics of multiplication formula in 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, 99 multiplication songs became popular. Its specific features are as follows:

General 1 and 99 tables only use 9 numbers from 1 to 9.

2. Table 99 contains the interchangeability of multiplication, so only 8972 is needed, and "9872" is not needed.

3. The shortest multiplication table in the ancient world. Maya multiplication table must have 190, Babylon multiplication table must have 1770, Egypt, Greece, Rome, India and other countries must have infinite items, and Jiujiu table only needs 45/8 1.

4. There is rhythm when reading aloud, which is convenient for memorizing the whole table.

Baidu encyclopedia-multiplication formula

Baidu Encyclopedia-Division in Table