-Turn math problems into real life.

The success of teaching depends largely on whether students' mathematical ability is cultivated, and the strength of mathematical ability depends largely on whether students can use what they have learned to solve practical problems.

Therefore, in mathematics teaching, how to make students "understand" that mathematics knowledge comes from and serves life, how to observe the reality of life from a mathematical perspective and cultivate the ability to solve practical problems should become a problem that every mathematics teacher attaches importance to.

The newly compiled mathematics textbook has created good conditions for teaching in this field from the aspects of concept formation, method induction and knowledge application. However, how to make use of these conditions, creatively exert teachers' subjective initiative, make mathematics teaching closer to the reality of life, and cultivate students' ability to solve practical problems needs our constant practice and exploration. Let's talk about this experience

First, abstract mathematical knowledge from real life.

Mathematics studies the quantitative relationship and spatial form of the objective world, which comes from the actual things in the objective world. In primary school mathematics teaching, starting from the reality of life, organically combining the content of teaching materials with "mathematics reality" conforms to the cognitive characteristics of primary school students, which can eliminate students' strangeness to mathematics knowledge and make them receive the enlightenment education of dialectical materialism.

1. Abstracts mathematical concepts and calculation rules from practical problems.

Many concepts in primary school mathematics can be found in real life. For example, in the common quantitative relationship "working hours? The "work efficiency" in "work efficiency = total work" is not easy for students to understand. To this end, I held a button sewing competition in my class before the lecture. When teaching a new class, students can easily understand work efficiency, which refers to the amount of work completed in a unit time.

For another example, the teaching of "brackets" can be carried out like this: first show "8 6?" And "6? 8 "two formulas, let students review the operation order. Then show the application problem:

The master worker works 3 hours in the morning and 4 hours in the afternoon, making 12 parts per hour. How many parts does he make a day? (Comprehensive formula is required)

The calculation method of student formula is as follows:

12? 4= 12? =84 (pieces),

The teacher wondered: It seems wrong to add first and then multiply, right? Reveal the contradiction between old and new knowledge and introduce brackets when students are at a loss. In this way, through the design of problems and the solution of contradictions, students can understand the reasons and uses of introducing brackets and the reason of counting the numbers in brackets first.

2. Starting from the reality close to the actual level of students, introduce concepts step by step.

For example, "area unit" can be taught as follows: first, show two triangles with obvious differences in size, let students compare their areas and draw the conclusion that the areas can be seen with their eyes; Then show two rectangles with equal width, unequal length and similar area for students to compare their sizes, and draw the conclusion that the area size can be compared by overlapping method; Then show a rectangle and a square with unequal length and width and similar area, so that students can compare the sizes. After careful consideration, students can draw squares, and then compare the size of the area by comparing the number of squares; Finally, show two figures with the same number of squares but obviously different areas to guide students to discuss. Why are the areas equal but not equal? From this practical problem, it is concluded that there must be a unified standard for the size of the box. At this time, it is "natural" to introduce "area unit". By organizing teaching in this way, students not only master the concept of area unit, but also understand that area unit is produced in the process of solving practical problems and is inspired by dialectical materialism.

Second, the use of mathematical knowledge to solve practical problems

Learning is for application. Therefore, teachers should cultivate students' awareness and ability to solve practical problems with mathematical knowledge.

1. Enhance students' mathematical consciousness in combination with reality.

Mathematical knowledge is widely used in daily life, and there is mathematics everywhere in life. After learning the stability of triangles, students can observe where the stability of triangles is used in their lives. After learning the knowledge of circle, ask the students to explain why the shape of the wheel is round and triangular from a mathematical point of view. Why? Students can also find out where the center of the basin bottom, pot cover and so on is. By understanding the extensive application of mathematical knowledge in practice, students are trained to see problems with mathematical eyes and think with mathematical minds, and their awareness of solving practical problems with mathematical knowledge is enhanced.

2. Create situations to cultivate students' ability to solve practical problems.

After students have mastered certain mathematical knowledge, they can consciously create some environments and apply what they have learned to real life. For example, after learning the knowledge of "proportional distribution", ask students to help calculate the electricity bill that each household in this residential building should pay; After learning the knowledge of "interest", calculate how much principal and interest you can get after the money deposited in "emerging small banks" expires.

After learning percentage knowledge, I played a game with my students. The method is: put six identical balls in a cloth bag and mark them with 1~6 respectively. Teachers and students take turns taking two balls out of the bag at a time. If the sum of the two numbers on the ball is even, the student wins and the teacher wins. The result of the competition is that the teacher won many times, and then led the students to discuss and list all kinds of situations one by one. It is understood that the sum is even in six cases and odd in nine cases. The teacher's chances of winning are 60% and the students' chances of winning are 40%, so the teacher has won many times. Finally, it is pointed out that some gambling activities in the streets and lanes engage in this kind of deception, so don't be easily deceived.

3. Strengthen the operation and cultivate the ability

Applying the mathematics knowledge learned in class to real life is often stumped by the complicated reality of life. We should strengthen practical operation and cultivate the ability to apply what we have learned. For example, after teaching "Ratio and Proportion", I intend to take the students to the playground and let them measure and calculate the height of Metasequoia glyptostroboides beside the playground. Metasequoia towering, how to measure? Most of the students shook their heads, and a few of them whispered to each other and proposed to climb up and measure, but how can they measure with their hands on the tree? Some people suggest taking the rope, measuring the tree with the rope first, and then measuring the rope after getting off the tree.

It's a good idea, but there's nothing to climb. How can I get up? The teacher took a 2-meter-long bamboo pole at the right time and inserted it straight in the playground. At this time, the sun is shining, and the shadow of the bamboo pole appears immediately, and the shadow length is measured to be 1 meter. Inspire students to think: since the length of the pole is twice that of the shadow, can you think of a way to measure the height of the tree? The student calculated that the height of this tree is twice as high as its shadow. (The teacher added "at the same time". After this idea was affirmed, the students quickly calculated the height of the tree by measuring the length of the shadow. Then, the teacher said, "Can you write a formula for finding the height of the tree in proportion?" So it is concluded that: rod length: rod shadow length = tree height: tree shadow length; Or: tree height: rod length = tree shadow length: rod shadow length. In this activity, students have increased their knowledge and exercised their abilities.