Everyone thinks that the third grade is a watershed for children to learn mathematics.
Experts said it was because of "application problems" in the third year. In the face of application problems, children must have the ability to understand, think, analyze and judge, and because of the different development of children, this ability broke out in the third grade.
Moreover, many of these mines have been buried since the first grade or even the lower grade.
For example, this question,
Four peaches for five people, one for each. How many pears are still missing?
Many children know the formula 5-4= 1, but it may not be enough for her to tell the meaning of the formula.
It shows that children's understanding is not thorough enough, and the most important thing in mathematics learning is to understand clearly and thoroughly. If there is a trace of ambiguity, it means that there will be related problems that cannot be solved tomorrow.
In fact, it is not easy to analyze this problem clearly.
First, we need to know what 5 and 4 mean.
If we ask children, they will say, 5 stands for 5 people and 4 stands for 4 pears. As a result, what's the difference between five people and four pears? The child will say 1 pear.
This involves a problem in mathematics, such as measuring and counting similar things, addition and subtraction.
In order to make students feel this, we must give examples.
How much is two people and two pigs? When students perceive absurdity, they can continue to ask, what does 4 mean?
draw
Then one-to-one correspondence, four pears can be distributed to four people, so four can also mean four people who are distributed to pears here, while 1 means 1 person who is not distributed to pears, corresponding to a pear of 1.
Therefore,
5-4= 1, that is to say, 5 people minus 4 people got the pear, and the remaining 1 person didn't get the pear, that is, one pear was missing. The mathematical ideas used here are very important.
In mathematics learning, understanding is very important, and the cultivation of understanding is to enable children to express their ideas clearly, especially their specific meanings.