Unit 5 is about one-to-one correspondence. According to the book, one-to-one correspondence is the most basic concept in the concept of number and the premise of counting. This clearly shows the importance of one-to-one correspondence. It is very likely that it is difficult for many first-year children to learn more, because the one-on-one relationship has not been established.
This reminds me of an open class, Tree Planting, which was taught by teacher Chen Jiacang in our school last time. Planting trees is the content of the wide-angle unit of mathematics in grade four. This course is difficult for some children. What is the reason after all? One is that students' thinking level is too low to carry out such high-level thinking activities. The other is the complexity of planting trees. There are three situations: one is to plant one end, the other is not to plant, the other is to fight at both ends, and the other is not to fight at both ends. The most important reason, as Mr. Chen Jiacang explained in the lecture after class that day, is that our rural students have no concept of one-on-one mathematical thinking.
I still remember that in class, Mr. Chen Jiacang has made it very direct and obvious about trees and intervals, that is, the division of points and segments, but the students still can't get in touch with one-to-one correspondence and have no clue. I think this may be the pain point of our rural students, who are unconscious of some mathematical ideas.
The mathematical idea of one-to-one correspondence is not only about planting trees in the fourth grade, but also when we compare numbers in the first grade, we also use this corresponding method to compare the number of two objects, even more than one object. When we teach this content in the first grade, we will make sure that the students are connected one by one or arranged neatly. After communication, it is convenient to see more and see less. Basically, we will stop here, and we will compare it like this. In fact, we have achieved our teaching goal.
But looking at the knowledge points of primary school mathematics, one-to-one correspondence is a very important mathematical idea in our primary school mathematics. It is not enough for us to just stay there. In teaching, we can make more efforts to help students establish a one-to-one relationship according to their pain points.
As mentioned in this book, in fact, one-to-one corresponding activities have already begun to develop as early as the baby's early perceptual motor activities, such as grasping one thing with both hands and only stuffing one thing into his mouth at a time. Then I realized that a person was sitting in a chair with a shoe on one foot, and so on. Children's daily lives are unconsciously corresponding to each other.
This book mentions structured activities to help children perceive one-to-one correspondence. In fact, for our primary school students, that is, the first grade is suitable for emotional activities training like this. take for example
[If! supportLists] 1。 ? [endif] Match items with different perceptual characteristics. Match the doll with the toy dog. This activity is to pair two different objects with the same number.
[If! Support list ]2. ? [endif] perceive different characteristics. Read the story "Three Little Pigs" and match three little pigs with different houses. Although they are all houses, the lack of houses is not the same as having houses, and it is a further upgrade of similar goods.
[If! Support list ]3. ? [endif] conforms to the real situation. Correspond the money, coins and toys used in life one by one, which is closer to the real life of children.
[If! Support list ]4. ? [endif] picture matching. Show pictures of two things that children are familiar with and match them. This is a re-abstraction of real object matching.
[If! Support list ]5. ? [endif] Similar or identical items. Use plastic sheets, hexahedral building blocks, playing cards, etc. Make them all the same color. This kind of matching is more difficult, and more complicated one-to-one perception activities are carried out.
[If! Support list ]6. ? [endif] Match the same number of items with dots. Make containers out of cans, etc. And match the stick with the same number of points on the container. This type of activity has developed from concrete image things to numbers and counting.
Teacher Wei Zhiyuan said that rote memorization is the most taboo in developing children's mathematical thinking ability in primary school. When I teach first-year students, it will be the same. In the face of students who can't even add a few, I will let them recite their compositions. Facts have proved that this has affected their development. The sixth unit of this book gives us more cases. We can establish important mathematical ideas through various forms of activities, interesting activities and increasing counting experience.