Teaching design of mathematics mixed operation in the second grade of primary school.
Teaching objective: 1. Knowing the operation sequence of multiplication and division can calculate the problems of multiplication and division and solve some simple application problems.
2. Experienced the process of trying to change two formulas of step-by-step calculation into a mixed formula of multiplication and division. Cultivate hands-on ability, independent exploration ability, cooperation and communication ability, experience the diversification of problem-solving strategies, and cultivate students' awareness of multi-angle observation and thinking.
3. Feel the application of mixed operation in real life in problem-solving activities.
Teaching emphases and difficulties:
Teaching emphasis: understand and master the order of multiplication and division in two-step operation, and correctly calculate and solve practical problems.
Teaching difficulties: enumerate comprehensive formulas to solve the problem of mixed operation of multiplication and division in two-step calculation.
Teaching preparation: multimedia courseware
Teaching process:
First, create situations and ask questions.
1, review old knowledge
Say the operation order of each problem and then calculate it.
12+4+30=
2×4×7=
36÷3÷2=
15+ 10-8=
Question: In the formula without brackets, when there are only addition and subtraction operations or only multiplication and division operations, what order should they be calculated?
2. Observe the situation map, find information and ask questions.
Students, last class, we explored the calculation order of continuous multiplication and continuous division through cube learning. In this class, we learned new knowledge through cubes.
Teaching design of mixed operation of mathematics in the second grade of primary school (part two)
Teaching goal: 1, knowledge and skills: master the operation sequence of the same level and be able to operate correctly.
2. Process and method: Understand the order of operations at the same level through the situation, and learn to solve mixed operations at the same level by disjunction.
3. Emotional attitude and values: cultivate good study habits and mathematical consciousness.
Teaching emphasis: master the calculation method at the same level and use the calculation correctly.
Teaching difficulty: understanding the operation order of mixed operation.
teaching process
First, check the import.
Oral arithmetic practice.
16+9+8 32- 10-6 25+20- 10 48-8+ 17
After the students have finished, the teacher corrects them.
Teaching intention: Through review, students are prepared for knowledge and psychology, paving the way for using transfer to learn new knowledge.
Second, independent learning, cooperation and exchange.
(A) careful observation, collecting information and solving problems
Question:
1. What are the students doing?
2. What information did you get from the picture?
3. How to calculate the formula?
Think for yourself and share your thoughts at the same table.
(2) Feedback and communication, summarizing the operation sequence.
Step by step calculation: 53-24=29 29+38=67
Comprehensive formula: 53-24+38=67
Summary: Only when adding and subtracting is it calculated from left to right.
(C) learning informal computing formats
53-24+38
=29+38
=77
Abstract: Equal sign alignment
(d) Consolidate the off calculation format and understand the operation sequence at the same level.
48-8+ 17 15÷3×5
Summary: In the formula without brackets, the calculation from left to right can only be addition and subtraction or multiplication and division.
Third, consolidate the practice.
(1) calculation
23+6- 1 1 2×8÷4 72÷8÷3
(2) Correcting mistakes
① 15-6+4 ②2×6÷3
= 15- 10 =2×2
=5 =4
The teacher instructs the students to analyze. If the first item is wrong, it should be 15-6 first.
The second item is wrong, it should be calculated as 2×6 first.
Verb (abbreviation of verb) course summary
What did you learn in this class today? What have you gained? Is there a problem?
Six, homework arrangement
Exercise 1 1 1, 2 questions
Teaching design of mixed operation of mathematics in the second grade of primary school (3)
First, the teaching content: P79 Second, the teaching objectives:
1. Cultivate students' ability to get information from pictures and ask questions.
2, combined with the specific situation, cultivate students' estimation ability.
3. Cultivate students' ability to solve and ask questions.
Third, teaching preparation:
Arithmetic card
Fourth, the teaching process
(1) review
1, oral calculation
Step 2 calculate
(2) Explore new knowledge
1. Create situations and ask questions.
Step 2 solve practical problems
(1) How much can Xiaogang save for his monthly living expenses in 980 yuan?
Students' independent estimation: 800+600- 1000 = 4000 (yuan)
About saving 400 yuan.
Actual calculation, classroom communication:
786+632-980 = 438 (yuan)
(2) If you want to buy a washing machine with 960 yuan's savings, how many months will it take?
Students think independently, discuss in groups and communicate with the whole class.
960-438 = 522522-438 = 84 Three months
438+438 = 876960-876 = 84 three months
3. Summary
4. Practice
(4) class summary
What is the order of addition and subtraction (without brackets)?
(5) homework