Current location - Training Enrollment Network - Mathematics courses - The trick of multiplication formula
The trick of multiplication formula
The trick of multiplication formula

The secret of multiplication formula is to learn addition, subtraction, multiplication and division in primary school. Our children in China have been taught multiplication tables since childhood. This is the easiest way to learn multiplication, but many people can't recite it. Let's take a look at the trick of multiplication formula.

Multiplication formula 1 Understanding mnemonics Understanding family

Elves who know the family are good at logical reasoning. When they can read out the formulas in sequence, there must be some formulas that they are familiar with, such as: 25- 10. From 1990 to 1980 and so on. Taking these formulas as reference objects, we can quickly find the adjacent multiplication formulas through calculation, for example, we can't figure out the result of 8×9.

Then you can think of "nine nines minus one nine", which means "8 1-9 = 72". Of course, you can't write 72 after reaching a conclusion, but you should also recite the formula of "8x9" in your mind. After so many times of thinking, the sentence "8972" will also become a formula to remember.

In this way, the effect should be more obvious from some formulas to all formulas.

How do parents teach their children to recite multiplication formulas

Say what it means

We should tell our children that the multiplication table is also called "99 multiplication table". As the name implies, this table consists of nine rows and nine columns. And the whole formula table is like a staircase shape. If children find and remember this feature, it is easy to remember the structure of the whole table in their minds and deepen their image memory.

Start with a word.

Tell your child to recite the multiplication formula table line by line. The first word at the beginning of each line must start with "one", and there are nine lines, and each line must start with "one". In this way, children will not be confused when reciting.

The number of rows is as follows.

It should also be noted that the first formula in each column is related to its row. What I just said is that the first word in each column starts with a "one". So, what about the second word? We found that the second word is the number of lines it is in, just look at the position of the box. Through these two characteristics, you can easily remember the first formula of each line.

Multiplication formula 2 1. Memory formula: emphasize experience, know the source and know the meaning.

People know things, and only what they understand is easy to remember and apply. So memorizing formulas should help students understand how multiplication formulas are derived and what each formula means. For example, if students forget, they can ask students: Where did the formula (1) come from? (7+7+7+7=28); (2) What do you mean? (Four sevens add up to 28)

Second, remember the formula: use the law of the formula itself.

To remember the meaning, we must understand the memorized materials, carry out positive thinking activities, find its connection with existing knowledge and experience, and make new materials become an integral part of existing knowledge, so that it is easy to remember. Even if you forget it temporarily, you can use reasoning to evoke memories.

You can use the multiplication formula table to memorize the formula in various forms, such as vertical back and back-turning. It can also help students find some rules in the table to memorize formulas.

For example, if you forget the formula "67", what are you going to do? At this time, students can memorize the formula according to the law: (1) add a seven according to five, seven and thirty-five; (2) According to 372 1, use 2 1 plus 21; ③ Press 6636 and add six;

You can also remember according to the rules, such as the multiplication formula of 9, and remember emphatically that "9 times several times gets dozens of times less". You can also spread out your hands and see how many you have. The specific method is: spread your hands so that they face up, bend the first finger from the left and straighten nine fingers from the right, which means "nine out of nine";

Bend the second finger from the left. There are 1 fingers on the left of the bent finger, and 8 fingers on the right of the bent finger are straight, indicating "298"; Bend the third finger from the left, there are 2 fingers on the left and 7 fingers on the right, which means "3927"; Wait a minute. Both methods make the formula of 9 easy to remember.

Third, the memory formula: through various forms of practice.

Memorizing all multiplication formulas requires a process, and it needs to be practiced from different angles in various forms to achieve the degree of blurting out.

(1) After the formula is compiled, read in groups, clap your hands while reading, and try to remember it, so you can learn it in time. Then through practice, the multiplication table calculation and formula calculation are paid equal attention at the same time, which deepens the impression of multiplication.

After the exercise, try to get the students to recite. Most students remember it easily. Then through group recitation, individual recitation, dragon recitation, deskmate recitation and other interesting forms. Students can effectively master oral decisions.

(2) In order to improve students' proficiency in multiplication formula and calculation efficiency, students' purely mechanical hands-on exercises should be changed into exercises involving brain, mouth and hands. The memory of multiplication formula is put into the game to produce unconscious memory, and its memory effect is often more labor-saving than rote memorization.

A. check the password.

B. guess the cards. Write a card before the activity. For example, 25, 16, 40, 9 ... Show the card for students to answer first, and say that the number on the card is the product of several times.

C, listen and win the championship. Let's talk about the formula first. Let's write the answers on paper quickly to see who writes them correctly and quickly.

The above game practice methods can improve students' proficiency and interest in oral arithmetic, and cultivate children's directional attention and thinking agility.

(3) Carefully design thoughtful exercises, such as designing multi-result fill-in-the-blank questions,

4×()=() ( )×( )=24

36=( )×( )=( )×( )=( )×( )

Let children strengthen their memory in practice. Practice more unforgettable formulas, less unforgettable formulas, and more confusing formulas. This method has many advantages: ① practice memorizing multiplication formula through variants; (2) lay a good foundation for the quotient of division (including division with remainder); ③ It is beneficial to cultivate students' reverse thinking ability and thinking flexibility.

Fourth, memorize multiplication formula in practical application.

Mathematics comes from life. The recitation of multiplication formula should be closely related to the reality of primary school students' life, find the application of multiplication, let students collect materials and experience the close relationship between mathematics and life. In this way, we can not only remember the multiplication formula, but also perceive the relationship between the structure and quantity of application problems. More importantly, we can let students feel that there is mathematics everywhere in their lives, thus enhancing their interest and motivation in learning.

The third trick of multiplication formula is to recite vertically:

There is a rule in this method, that is, the number of digits in the vertical column increases gradually, which can help memory.

Recite horizontally:

There is another rule in this method. In the first few lines, the last sentence is a few more than the previous one.

Recite in turn:

One of the characteristics of this recitation is that there are nine sentences in the formula from one to nine, and several formulas will gradually increase.

To form a long-term memory, you can recite it for two minutes every day (divide the day into two periods and recite it for ten minutes in each period), choose a recitation period at random, and write it on paper while reciting, which will deepen the long-term memory.

Learn to understand without reciting (for example, five five twenty-five, this is five five plus twenty-five,). We should also skillfully use the peripheral relationship of this formula (for example, six seven forty-two, forty-two plus one seven equals forty-nine, forty-two minus six equals thirty-six, etc.). ) so as to strengthen the use of multiplication tables.