Are there any rules for the multiplication formula table in the third grade of primary school?

The ninety-nine multiplication table is a systematic collation of the multiplication formulas that children have learned, and there are many rules hidden in the table, some of which are exposed to in class, and some are brand new, but there is one thing that remains the same, and children need to discover it themselves.

After the children observed on their own, they found a lot of patterns. Horizontally, the first number gradually increases, and the second number remains unchanged; The first few lines are the multiplication formulas of several (when it comes to this, I didn't let the child say it, because I think the point has been said, I'm afraid it's too late, so I said that the rules of each multiplication formula we've already talked about, so I won't say it, I feel that the handling is not good, and the children should be asked to recall their rules); Vertically, the first number in the first column is 1, the second number gradually increases, and the number gradually increases by 1, and then the second column and the third column (I then guide the child to summarize the first number in the first column of formulas is the number, and the number gradually increases); Looking from left to right, the mantra gradually decreases by 1; There are a few sentences of the formula, and the product of the last sentence of the formula is a few (it is true, but I don't understand why, although this finding does not seem to help children memorize the formula, but it is a law to have to multiply); Diagonally, the first two numbers of the first line of mantra are the same; The second number of the mantra before the second line is the first number of the mantra in the next sentence, and the first two numbers of the mantra after the third line are 1 larger than the first two numbers of the mantra in the previous sentence, and the following ones also have this law (in fact, the second line is also like this rule, but it happens to be like Solitaire). Look around, although I have been in contact before, but only very good children remember how to see, under my prompting, look at know how to see, and also found a mantra that is related to a few.

The child is really amazing, found a lot of rules, but because there are too many children who want to speak, looking at their anxious look, I can't help but invite him, in the end there is more time to say, less time to memorize, they found so many rules, but they are not used to memorize the formula, I think I didn't deal with it well. However, there are children in our class who are diagonally backed, which I think is quite remarkable, because some children remember it along the back, and they can't be smoked casually, but I found that they all remember it diagonally.

The child's vision is always so unique, and I admire it!

The rules of multiplication tables are:

1. Any number multiplied by 1 equals the number itself.

2. Any number multiplied by 2 can get an even number, and the last digit of the product appears 2, 4, 6, 8 twice, and 0 once.

Multiply each digit from 1 to 9, the last digit of the product is 1 to 9, and the sum of the ten digits of the product and the single digit is a multiple of 3.

4. Any number multiplied by 4 can get an even number, and the last digit of the product appears 2, 4, 6, 8 twice, and 0 once.

5. The last digit of the product of any number and 5 can only be 0 or 5.

The multiplication formula (also known as "ninety-nine songs"), as far back as the Spring and Autumn Period and the Warring States Period, ninety-nine songs have 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 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".

<>Significance

3 5 means 5 3's are added.

5x3 means the addition of 3 5s.

New meaning of multiplication: Multiplication is not a simple notation of addition.

If the dependent variable.

f with independent variables.

x1,x2,x3,….There is a direct proportionality between xn.

relationship and each independent variable is different in perturbation of the spinal mass, and the absence of any one of the independent variables loses its meaning because of the Lie Stove variable f, which is multiplication.

The above content reference: Baichun dress up - multiplication.

<> multiplication formula is learned in the second grade of primary school, starting from "one by one to get one" and ending with "ninety-nine eighty-one", also known as ninety-nine tables, ninety-nine songs, nine-cause songs, and ninety-nine multiplication tables; The ninety-nine table has a history of 2,000 years and is the basic rule of multiplication and division and square operation in ancient China.

Summary of Mathematics Knowledge for Primary 1 to 6 Grades:

Primary 1: 99 multiplication formula, learn the basics of addition, subtraction and multiplication: memorize the 99 multiplication formula, so that you are familiar with the multiplication of single digits;

Primary 2: Improve the multiplication formula, strengthen the knowledge of the first grade, learn to divide the mixed operation, and basic geometric figures;

Primary 3: Learn the commutative law of multiplication, geometric area, circumference, etc., the amount of time and units. distance calculation, distributive property, fractional decimals;

Primary 4: Line angles, natural numbers, integers, prime factors, trapezoidal symmetry, fractional decimal calculation;

Primary 5: Multiplication and division of fractions, algebraic equations and averages, comparative size transformations, graph area volumes;

Primary 6: Proportional Percentage Probability, Fan Cylinder and Cone.

The multiplication formula is the basic calculation rules for multiplication, division, square and other operations in ancient Chinese calculations, which have been used for more than 2,000 years.

The ancient multiplication formula is from top to bottom, starting from "ninety-nine eighty-one" to "one by one", which is contrary to the order of use, 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, ninety-nine song, nine-nine song, ninety-nine multiplication table.

The rules of multiplication:

Digit alignment, starting from the right, use the number on each bit of the second factor to multiply the first factor, and whichever digit is multiplied, the end of the number will be aligned with which digit of the second factor.

1. The number of tens is the two-digit multiplication method of 1: the unit digit of the multiplier is added to the multiplier, and the number is the front product, and the unit digit of the multiplier is multiplied by the unit of the multiplier, and the number is the back product, and the number is full of ten.

2. The single digit is a two-digit multiplication method of 1: multiply the ten digits with the ten digits, and the number is the previous product, and the ten digits are added to the ten digits, and the number is then written, and the full ten digits are added to one, and 1 is added at the end.

3. The two-digit multiplication method of ten digits with different single digits: the multiplier is added to the multiplier digit, and multiplied by the ten-digit integer, the product is used as the first product, and the single digit is multiplied by the single digit as the back product.