Method means "how to teach" and means means "what to teach"
Carry Addition 20 in Unit 9
Unit point analysis:
First, the content of the textbook: P96-P 1 1 1.
There are two main contents in this unit. One is the addition of two digits with numbers exceeding 10, which is simply described as "carry addition within 20"; Second, "using mathematics" means using addition and subtraction to solve simple problems.
The calculation part of this unit is divided into three sections, namely 9 plus several, 8, 7, 6 plus several, 5, 4, 3, 2 plus several. This arrangement reflects the repeated understanding process of learning knowledge and forming skills. "Applying Mathematics" in the textbook is arranged in calculation, which requires students to observe and discover mathematical problems, collect information and data needed to solve problems, explore methods to solve problems, and obtain the whole process of solving problems.
Second, the teaching objectives:
1, let students skillfully calculate the carry addition within 20.
2. Let students learn to use addition and subtraction to solve simple problems.
3. Through mathematics learning, students can experience the close relationship between mathematics and daily life and feel the role of mathematics in daily life.
Third, the difficulties in teaching:
1, hands-on operation, let students understand and master the "add ten method" and find the law of carry addition within 20.
2, gradually abstract, prompting students to calculate numbers through thinking.
3. Ways to solve application problems with pictures and words.
Fourth, the application of teaching methods:
1, make full use of the theme map.
2. Let the students set up sticks.
3. Let students skillfully calculate with a verbal card.
Five, teaching methods:
1, independent inquiry, cooperative communication mode.
2. Observation and physical operation.
Six, teaching ideas:
9 plus a few
This textbook begins to teach oral arithmetic of carry addition within 20. The textbook is divided into two sections, the first section is the oral calculation of 9 plus several, and the second section is "using mathematics".
This part of the content can be taught in three classes. The content of teaching 9 plus a few can be arranged in 2 class hours, and mixed exercises of consolidation exercises can be carried out in class. To complete the exercise of exercise 17, you can arrange the content of "applying mathematics" in 1 class, do the addition and subtraction within 9 and 10 in class, and complete the exercise of exercise 18.
When teaching examples, there should be a panoramic wall chart and slide projection (courseware) of the sports meeting, and vivid game scenes should be described in language to attract students to "enter".
When teaching examples, let students pose by themselves and experience the process of ten addition in operation, so as to understand the arithmetic of carry addition and master the calculation method. For example, when calculating the acceleration of 9, ask students to put 9 red sticks on the left and 3 green sticks on the right, and then inspire students to think: 10 how to make up? You can play it several times more, so that students can form the appearance of making up ten in their minds, which can deepen students' understanding of the methods of making up ten and help them master it better.
What's eight, seven and six?
This part can be taught in 4 class hours. You can arrange the contents of teaching 8, 7 and 6 in two classes, and carry out consolidation and mixed exercises in the class to complete the exercises in exercise 19. You can arrange the content of "Applying Mathematics" in two classes, and practice the carry addition within 20 and the addition and subtraction within 10 in class to complete the exercise of Exercise 20.
When teaching example 1, on the basis of learning how to add several to nine, let students independently put out the process of adding eight to 10 with wooden sticks to deepen their perceptual understanding of the method of adding ten. On the basis of operation, let the students tell the oral calculation process of adding up 10 to calculate 8+5, which strengthens the understanding that if you add up to 10, you can divide another addend by 2 and several, laying a good foundation for students to master the calculation method of adding up to 8.
Example 3 When teaching, let the students calculate 8+9 independently, and the teacher guides the students to say the calculation method.
Five, four, three, two plus a few.
These contents require students to complete these calculations with what they have learned. Page 1 10 of the textbook "Review" to review the carry addition problems learned earlier. Prepare to calculate the addend of 5, 4, 3 and 2 by the exchange addend method.
This part of the content can be taught in three classes, teaching 5, 4, 3, 2 plus several classes, and carrying out consolidation exercises and comprehensive exercises in class to complete the exercises in exercise 2 1.
Example 1 (page 1 10) There is a picture of a teacher's problem under 5+7= 5+8=, which is intended to guide students to work out numbers with 7+5 and 8+5, so that students can learn to exchange addends initially.
The example (page 1 10) only gives the formula. Ask students to calculate the number of 4+8 3+9 with the learned 8+4 9+3, and consolidate the calculation of decimal addend with the exchange addend method.