The reasons are as follows: First, the language and writing obstacles of practical problems limit students' ability of analysis and understanding. As a result, they can't figure out the relationship between known conditions and known conditions and problems. Second, I don't understand the problem to be solved, that is to say, I don't understand the requirements and the meaning of the problem. Being in a blind state often makes mistakes.
Graphic method is very effective to solve this kind of problem.
For example, there was a question in the students' practice garden in the last semester of grade five: a car traveled from place A to place B, 240 kilometers apart, driving for three hours, and there were 39 kilometers left. How many kilometers does this car average per hour?
Hardly had I copied the question on the blackboard when two or three students shouted, "80 kilometers per hour." I smiled and asked one of the students, "How did you work it out?" The student replied without thinking, "40 kilometers divided by 3 equals 80 kilometers." I still smiled and said, "it's good that you can speak on your own initiative!" " Please sit down! "
Please think about it: have you used up the known conditions in the question? Is the remaining 39 kilometers redundant? Read the original question again and look at the chart on the blackboard. So, I drew a line sketch on the blackboard:
_ _ _ _ _ _ 240 km _ _ _ _ _ _ _ _
A/———————————— \ b
\-3 hours -/\-39 kilometers-/
Hint: The conditions given in this question: The total distance between Party A and Party B is 240 kilometers, and after driving for three hours, there are still 39 kilometers left.
Question: 1 Did you cover the total distance of 240 kilometers in three hours?
2. The total distance is 240 kilometers, and there are 39 kilometers left. What is their relationship? Look at the picture. Do you feel any figures hidden between these figures? In other words, the car only traveled a part of the distance between Party A and Party B in three hours, not the whole journey.
Thinking Tip: Is the implied figure a three-hour trip? Only by knowing this distance can we know the speed of the car and achieve the purpose of answering questions.
Look at the picture again, 240 km-39 km =20 1 km, which is a three-hour drive.
Guide students to draw and analyze, and find the solution to the problem. Let the car travel at the speed of x kilometers per hour, and the formula is:
3x = 240-39 Solution x=67 (km/h)
Through the above drawing and reading analysis, most students in the class have mastered the solution of this kind of problem.
It can be seen that graphic method plays a great role in the teaching of mathematical application problems in primary schools. First, through drawing, reading and analyzing pictures, we can enhance the complementary and rich effect of pictures and texts, stimulate students' interest in learning mathematics and improve their enthusiasm for learning mathematics. Second, by drawing and reading pictures, the abstraction is turned into visualization, and the students' analytical understanding ability is enhanced.