Example 1: Write a division formula with a remainder of 3.
Wrong solution: 15 ÷ 2 = 6...3
Analysis: The answer to this question is because students forget that in the division formula with remainder, the remainder must be less than the divisor, but in the so-called calculation, the most fundamental requirement of the division formula with remainder is not wrong.
Correct answer: 15 ÷ 6 = 2...3.
There are () 10: 480 in Example 2.
Wrong solution: There are (8) tens in 480.
Analysis: due to lax examination of the questions, there are four hundred and eight tens in 480, which leads to misunderstanding of the meaning of the questions.
Correct answer: There are (48) tens in 480.
Second, the mentality.
For example, we often meet students who use addition as long as there is "one * * *" in the question and subtraction as long as there is "surplus" in the question, regardless of the internal relationship between the question and the condition, so that "how much does it cost to buy eight books for each 2 yuan?" Plus 2+8= 10. So how to solve this problem? First, let students understand the meaning of addition and multiplication. Addition is the operation of synthesizing two arrays into a number, and finding "a * * *" is only one of the application problems of addition. The purpose of our teaching is to make students understand that if several numbers are combined, we must use addition instead of "a * * *".
Third, not understanding the meaning of the question leads to mistakes.
For example, there are 23 teachers and students, and each boat is limited to 4 people. How many boats should we rent at least?
Wrong answer: 23÷4=5 (only) ... 3 (person)
A: At least five boats must be rented.
The obtained quotient and remainder are direct answers, without considering other life factors. Students gradually formed the habit of answering after calculating. Moreover, this topic can be found in life, which is a rare typical topic close to life. Therefore, the answer needs to be linked with the reality of life. As long as the teacher gives a little guidance, students can wake up or understand that "the extra three people must be a boat!" These children don't understand the value of life. In order to solve the problem, they must solve it. Therefore, mathematics learning should also cultivate students' ability to connect with real life. Let students walk into life and truly feel that math problems come from life and serve life.
Example: Grade two students go to the movies. Tickets were issued first 198, 244 tickets were issued, and 35 tickets were issued more. How many people went to the movies in the second grade?
Wrong solution: 198+244=442 (Zhang)
442+35=477 (Zhang)
Analysis: the wrong solution of this question is due to the lack of attention to examination or analysis, which leads to the wrong solution. 198 244 tickets were issued after the tickets were issued first. There are already many tickets at this time, and 35 tickets is not much!
Fourth, careless calculation leads to errors.
Looking at all the wrong questions of children, the most wrong ones are the mistakes of children's understanding and calculation. Of course, it is not impossible, it is caused by carelessness.
For example, in the process of oral calculation, vertical calculation and problem solving, there are always some children who lose points because of calculation errors.
Such as multi-digit addition and subtraction of continuous abdication, either forgetting to carry or abdicate, or carrying or abdicating without carrying or abdicating.
In short, from the above erroneous analysis, we can easily see that some children just belong to the basic knowledge and basic skills are not solid; Some did not carefully examine the questions and did not understand the meaning of the questions; Also have a plenty of lack of practical experience and so on. These are all things that we should pay attention to in the review process, and try to avoid making the same mistake again in the future!