First of all, talk about textbooks.
1, lecture content:
Mathematics (People's Education Edition) "Compulsory Education Curriculum Standard Experimental Textbook" Volume II, Grade 5, page 69, Example 1 and 2.
2, the status and role of teaching materials:
Students have a preliminary understanding of fractions in the third grade, but the fractions they learned at that time were all fractions with numerator less than denominator. Therefore, learning this section plays an important role in making students fully understand the concept of fractions and cultivating their sense of numbers.
3, the determination of teaching objectives:
Today's era is an era of economic globalization, cultural diversity and social informatization, and education should also keep pace with the development of the times. Following the educational concept of "for the development of every student" put forward by the curriculum standards, the teaching objectives of this course are determined as follows:
① Let students understand the meaning of true score and false score;
(2) To deepen students' understanding of the meaning of scores by learning the true and false scores;
(3) Make students master the characteristics of true score and false score;
④ Cultivate students' abilities of observation, comparison, analysis and generalization;
⑤ Let students experience the joy of learning mathematics and the joy of success in thinking and discussion.
4. Teaching emphases and difficulties:
Understand and master the meaning and characteristics of true points and false points.
5, teaching preparation:
Some square pieces of paper.
Second, talk about teaching methods and learning methods.
This is a teaching of mathematical concepts, and students' cognitive construction of mathematical concepts is from intuitive to abstract, so I mainly adopt the teaching thread of "stimulating interest-exploring-constructing-deepening", and adopt intuitive teaching method and guided discovery method.
Curriculum standards point out that the core of learning style is thinking style, which is related to people's lifestyle. The way to learn today is the way to live and survive tomorrow. Therefore, learning style is very important.
The students in this class are proactive, expressive, curious and have a certain understanding of scores. I boldly let them learn through independent inquiry, cooperation and exchange.
Third, talk about teaching procedures.
Fourth, the teaching process
(1) import
1. Review: What is a score?
2. Use scores to represent the colored parts of the following pictures. (showing teaching AIDS)
Ask the students to say the meaning of each score separately.
(B) Teaching implementation
1. Question: Compare the numerator and denominator of the above three fractions? Are these scores greater than 1 or less than 1? And explain why.
2. After the students observe, try to answer.
Student: (The first square) is divided into four parts on average, so' 4 parts is a whole circle, representing 1, while the shaded part is only 1, so it is smaller than L.
Ask the students to name the other two scores respectively.
The teacher pointed out that the above four scores are true. Most of the scores we used to contact were true scores. So, can you tell me what a real score is?
4. Let the students think independently, talk to their deskmates, and then call the roll.
5. Summary: Fractions with numerator less than denominator are called true fractions. The true score is less than 1.
6. The teacher shows the graphic teaching aid in Example 2.
7. Ask the students to represent the shaded parts in each group of graphs with scores respectively.
Question: In the first picture, how many parts is a circle divided into? How many copies? How to express it in fractions?
The teacher emphasized that each circle in the second and third pictures stands for "1".
8. Compare the size of fractional numerator and denominator, and then compare with 1. Look at the pictures, try to compare them and communicate with your deskmate. The teacher named the answer: the shaded part occupies the whole circle, so it is equal to1; The indicated shaded part accounts for more than 1 circle, and the indicated shaded part accounts for more than 2 circles, so the sum is greater than 1.
9. The teacher pointed out that such a score is called a fake score. False score is greater than or equal to 1.
Ask the students to give some examples of false scores and guide them to give more false scores with the same numerator and denominator.
10. Guide students to complete the "doing" on page 70 of the textbook.
(l) Students should independently complete the 1 question and then correct it.
(2) Students independently complete the second question, and guide students to observe: On which section of the straight line are the points representing true scores and false scores?
(3) Thinking training
1, in the score, when a is less than (), it is a true score; When a is greater than or equal to (), it is a false score.
2. In the score (a>0), when a is less than or equal to (), it is a false score; When a is greater than (), it is a true fraction.
3. the unit of the score is yes. The lowest true score is (), and the lowest false score is ().
4. Write two true scores greater than () and ().
5. Judge right or wrong.
(1) A score less than 1 is a true score. ()
(2) The false score is greater than 1. ()
(3) False score is greater than or equal to 1. ()
(4) The true score is less than 1. ()
(5) Scores greater than 1 are false scores. ()
(6) A score equal to 1 is also a false score. ()
Verb (abbreviation of verb) course summary
Through the study of this lesson, we know the characteristics of true marks and false marks. The numerator of the true fraction is less than the denominator, and the true fraction is less than 1. The numerator of a false score is greater than the denominator or the numerator is equal to the score, and the false score is greater than or equal to 1. Through learning, correctly distinguish which score is true and which score is false, and correctly apply concepts to solve problems flexibly.
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