What are the multiplication formulas? What is a multiplication formula?

The ninety-nine multiplication formula is as follows:

The "little ninety-nine" mantra that primary school students learn starts from "one by one gets one" and ends with "ninety-nine eighty-one", but in ancient times, it was reversed, starting from "ninety-nine-eighty-one" and ending with "two-two-two-four". Because the first two words of the formula are "ninety-nine", people refer to it as "little ninety-nine". It wasn't until about the turn of the century that it was reversed like this, "one by one......Ninety-nine-eighty-one".

At present, primary school students learn the "little ninety-nine" formula, starting from "one by one to get one" and ending with "ninety-nine-eighty-one", but in ancient times, it was reversed, starting from "ninety-nine-eighty-one" and ending with "two-two to bury four". Because the first two words of the formula are "ninety-nine", people refer to it as "little ninety-nine". It was only about the turn of the century that it was reversed, as it is now, "one by one, one to ninety-nine, eighty-one."

Ancient Babylon had a multiplication and carry system very early, but the operation process was simple and fast, and the empty disadvantages were not easy to remember.

The multiplication formula table for modern elementary school students is:

The multiplication formula (also known as "ninety-nine songs") has been produced in China for a long time. As far back as the Spring and Autumn Period and the Warring States Period, Jiujiu Song has been widely used by people. In many writings of the time, some multiplication formulas have been cited.

The original ninety-nine song is from "ninety-nine-eighty-one" to "two-two-two-four", with a total of 36 mantras.

The excavated "bamboo and wood slips" of the Han Dynasty and the ancient "Jiujiu Shu Remnant Wood Slips" found in Dunhuang all started from "9981". The name "ninety-nine" is the first two words of the formula. Around the 5th and 10th centuries AD, the mantra "ninety-nine" was expanded to include "one and one as one".

It was only around the Song Dynasty (A.D.) that the order of the ninety-nine songs became the same as that used in modern times, that is, from "one to one as one" to "nine nine eighty-one".

The 45 formulas contained in Yuan Zhu Shijie's book "Enlightenment of Arithmetic" have changed from "one by one" to "ninety-nine", and are called the nine-number method. There are two kinds of multiplication formulas used, one is 45 sentences, which is usually called Xiao Jiujiu; There is also an 81-sentence one, which is commonly known as the big ninety-nine. It is recorded in the book that Da Jiujiu was first seen in the "Algorithm Dacheng" written by Chen Jie in the Qing Dynasty.

Multiplication Oral Brigade Recipe Table

5=10, 5=25

7=14, repentance 7=49

Multiplication: Factor x Factor = Product.

One factor = another factor.

The commutative law of multiplication: the commutative law of multiplication: the position of two numbers is multiplied, and the position of the two factors is exchanged, and the product is unchanged, which is called the commutative law of multiplication. a×b = b×a

The associative law of multiplication: multiply three numbers, multiply the first two numbers first, and then multiply the third number, or, multiply the last two numbers first, and then multiply the first number, and the product remains the same. This is called the associative law of multiplication. a×b×c = a×(b×c)

Calculation method: A common method of using a pencil and paper multiplier requires the storage of a small number (usually any two digits from 0 to 9) or a multiplication table for a quiet inquiry, but a farmer's multiplication algorithm is not.

Multiplying a number by more than a few decimal places is tedious and error-prone. Universal logarithms were invented to simplify this calculation. The slide rule allows the numbers to be quickly multiplied by about three degrees of accuracy.

Beginning in the twentieth century, mechanical calculators, such as the Marchant, multiplied by 10 digits. Modern electronic computers and calculators have greatly reduced the need for manual multiplication.

The multiplication formula is the basic implicit calculation rules for multiplication, division, square and other operations in ancient Chinese calculations, which have been used for more than 2,000 years, and the ninety-nine table is also the basic skill of arithmetic in primary school.

The multiplication formula in ancient times was from top to bottom, starting from "ninety-nine eighty-one" and ending with "one by one", which was the opposite of the order used, so the ancients used the two words "ninety-nine" at the beginning of the multiplication formula as the name of this formula, also known as ninety-nine table, talking about Laozhou ninety-nine songs, nine-cause songs, and ninety-nine multiplication and wax tables.

Ninety-nine multiplication formulas:

The "little ninety-nine" mantra that primary school students learn starts from "one by one gets one" and ends with "ninety-nine eighty-one", but in ancient times, it was reversed, starting from "ninety-nine-eighty-one" and ending with "two-two-two-four". Because the first two words of the formula are "ninety-nine", people refer to it as "little ninety-nine". It wasn't until about the turn of the century that it was reversed like this, "one by one......Ninety-nine-eighty-one".