Last week, I learned the Preliminary Understanding of Multiplication Formula, and the children mastered the meaning of multiplication formula well. Since last week, children can't wait to learn multiplication formula. Yes, the two blocks of multiplication learning are meaning and formula. Meaning comes first, then formula. Without a formula, multiplication would not be so simple. So, where does the multiplication formula start? The arrangement of teaching materials starts from 5, not 2, 3 and 4. Why is this happening? The biggest reason is the relationship with manpower. We have five fingers in each hand, which is absolutely intuitive. Then, two hands have 10 fingers, five numbers, and every two numbers will be ten, which is very rhythmic. So, our multiplication formula starts with 5.

Classroom content

The multiplication formula of positioning 5 is related to hands. So, the example I designed is "collecting fingerprints".

As soon as the topic came out, the children immediately looked at their hands and I asked:

"How many fingerprints should a handprint collect?"

The children immediately replied, "Five."

"Two hands?"

The children looked at their hands and quickly responded, "Ten!"

Keep asking questions and the children will answer them soon.

So, we entered the second section-the discussion of addition and multiplication corresponding to charts:

I asked, "If you use points to represent the index of your hand one by one, how many points does a hand need?"

"Five!"

"Well, how can we express it by multiplication?"

"5× 1 or 1×5"

"Yes, the students answered very well. As can be seen from this sketch, if you look horizontally, there are 1 in each row and five lines, that is, there are five lines in each column, and each column has 1, that is, the five lines have 1. "

"So how many points are used to represent the fingers of both hands?"

"Five more!" The children replied.

"Addition is 5+5= 10. How to express multiplication? "

"5×2 or 2×5"

"Who can tell the meaning?"

Many children raised their hands and said that the atmosphere was very warm!

"Then let's talk together!"

"Look horizontally, two in each row. How many twos are there in * * *? "

"Five!"

"Vertically, there are five in each column. * * * How many fives does it add up to? "

"Two!"

"So, our multiplication formula is ...? "

"5×2 or 2×5!"

The children were very excited, so we continued to talk, from concept map to addition, from addition to multiplication, explaining the meaning of multiplication every time. This continues until five fives add up.

What is the purpose of saying this? First, let children understand the relationship between addition and multiplication, and further consolidate the meaning of multiplication. )

Then I asked a question: "Can you think of a good way to remember the results of these multiplications? Let's solve the problem of multiplication calculation quickly, and don't go back to addition calculation when multiplying. "

A child whispered, "The formula of multiplication ..."

"Yes, we need to make up a multiplication formula, like a martial arts secret, to help us get the result of multiplication quickly! Who will try to edit it? "

The special students raised their hands and said, "15 gets 5,2510,3515,4520,5525."

I didn't expect to speak so professionally. Great! )

Nan raised his hand and added, "6530,7535."

I concluded: "Both students said it was very good. We can only study until five o'clock, five o'clock and twenty-five o'clock today! " "

Next, we clap our hands at the same table and say the formula. In two minutes, we will show the formula challenge, and the children will show it very actively. We will also ask and answer questions quickly, and the children's response is also very fast!

22 minutes have passed, leaving 18 minutes. The children have already started practicing. What are they practicing? Of course, that's a calculation related to 5, for example, how many angles do several five-pointed stars have? How many sides are there in several pentagons? There are also corresponding solutions to problems and so on.

When the bell rang, it took the children 18 minutes to finish the printed pages of textbook exercises 10 and classroom expansion exercises. All the children in the class have finished, and I have recognized it. The correct rate of the whole class reached a new high of 99%, and only a few students missed a small mistake such as a word.

postscript

The study of multiplication formula has begun, and there are still many multiplication formulas to learn, and this is our martial arts secret book and secret weapon for calculating multiplication formula!

Second, the preliminary understanding of mathematics-multiplication-

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