1 - 5 Canadian understanding of subtraction

 (a) teaching materials

content of this unit has two main parts. 5 less than the number of part knowledge, the other is 5 less than the number of addition and subtraction. Arrangement of the unit: first teaching 1 - 5 Canadian subtraction knowledge, understanding and processing in the teaching subtraction 0. This part of the attempt to choose the appropriate method number 5 within the mouth of calculation, the usefulness of mathematics for the students to understand and experience the fun of mathematics learning to lay a solid foundation.

(b) of the teaching objectives

1,UGG boots clearance, so that students with 1 - 5 The number indicates the number of objects, that 1 - 5 of the number sequence that can recognize and read 1 - 5 The few, the establishment of the initial number sense.

2, students initial observation and hands-on skills.

3, mutual exchange of experience and peer learning fun.

4, to enable students to perceive Life is full of mathematics.

(c) of the textbook description of some of the materials

This includes 1 - 5 of the base meaning, people read and write, the number of the order, than the size of the first of several (ordinal meaning) and a few and a few (the number of components) of six parts. This is the number of teaching the basic structure.

1,1 - 5, and the meaning of the number of base recognition, reading.

textbook 14 - 15 pages, by allowing students to see wild animals, artwork, a few people and objects in the figure, abstract 1 - 5 of the number of students while protecting wildlife, environmental education . Is obtained the number of people or things in a few number of specific basis. Shown with

after each abstract a number of all square as the background to the glyph display the print for students to recognize and read. Then, the abstract number of students in various physical and chemical root of the corresponding number of small sticks and placed into their own experiences in the geometry. Through the above from concrete to abstract, from the abstract back to specific cognitive processes, so that students initially perceived the number of 1 to 5 of the base meaning, and will recognize, read the 5 number.

2.1 ~ 5 the order.

textbook page 16, arranged in two levels of the order of 1 to 5. First use of the counter, so that students set aside on a counter from 1 to 5 beads. Allocation methods are: starts at 2 in the original, based on a bead, on a dial to get the next number. Visual perception through the operation so that students are in front of each number 1 after a few get added.

Then came the idea to map a rectangular background. Enable students to put ideas through the map, from the grasp of the whole number of 1 to 5 of the order. But also on a perceptual rectangle.

3.1 ~ 5 of the writing.

materials on page 16, with the image of the dotted line plus arrow outlines ways of writing 1 to 5, so that students know where to look started to write, how to turn, where revenue pen. At the same time provide materials for students to write numbers to imitate the practice grid, so that students learn to write numbers in the beginning, take the direction of strokes and each number in the grid layout in one hand, laying the foundation for the independence of the numbers written on the other hand beauty education so that students know how to layout a number, how to write it beautiful, beautiful.

4. Than size.

materials arranged into two levels. On page 17, first let the students observe the prototype form charts, we call it pictogram charts.

charts based on pictograms, drawn by a monkey and one of the fruit content of two columns on the quantitative comparison between the introduction of students to recognize signs The three symbols and their meanings, and knowing that the three symbols of the read method and the role of the students in the initial perception of symbols in mathematical functions and irreplaceable role in the text.

5. The first of several (ordinal meaning).

textbook page 18, close to the lives of children through a ticket plans, the number of tickets for students in the process of human perception of the natural order of the number of other meanings ─ ─ ordinal meaning.

6. Few and several (the number of components).

textbook page in 19,20 arranged in two levels from 2 to 5 the number of components. On page 19 to Teachers guide students through the activities put students come safflower 4 components: the same time tell the students how to read. On page 20 for students to form cooperative groups to explore the composition of law 5. Through the two-level operational activities so that students have mastered the 2 to 5 the number of components, with 5 or less for the later study the number of addition, subtraction calculations to prepare.

teaching suggestions

1 ~ 5 of awareness

(14 ~ 22)

1. This section can be 3 hours of instruction. Teaching numbers from 1 to 5, the base of the meaning and recognition, reading and writing, the order of 1 to 5, than the size of the first of several (ordinal meaning), a few and a few (the number of components), the completion of exercises to practice II.

2. Section 14 of the textbook on page 15 the number of 1 to 5 of the meaning and acceptability of the base, the teaching of reading, made the following comments for reference.

(1) guide the students to see the first 14 to 15 on the textbook illustrations. Computer courseware can also be made: first show a teacher with four children to the wildlife park, an elephant appeared one by one, two rhinos, three antelope, three giraffes, four birdies and float to the sky 4 white clouds and so on. Figure by students (or see courseware), causing students to observe the interest and stimulate the curiosity of students.

(2) allow students to small groups to talk about people and things which the figure, and one by one the number is 1 to 5 people or things. Number of students in order to guide the first few numbers of small, then the number of large number. Based on the number in the group, launched on behalf of students in the class number is 1 out of 5 people or things. Each student wrote one, that is, painting in the subject shown below the corresponding number of objects. For example, students said: Under the map labeled

teaching students recognize the numbers 1 to 5, the first print to teach, then teach writing body. To enable students to better remember the shape, allowing students to talk about each number something like life. Such as: 1 as a small stick, like a duckling 2, 3 as the ears, like the flags 4 and 5 as the scale hook. Computer Courseware by these figures with the corresponding graphic linked to enhance the students shape memory, while increasing interest in learning.

(3) 1 to 5 in the initial understanding and awareness of the meaning of the 5 numbers later, to organize students from the abstract back to concrete operational exercises. Can ask: platforms display.

(4) textbook on page 16, Activities, teachers produce three apples, and apples require students to produce as many other objects, or the number of cards with the number 3, said Apple. Teachers can also change the number of apples, students expressed the same amount of objects. Example, students can also talk about life around what is the object number 1,2,3,4,5.

3. Teaching number sequence from 1 to 5.

teaching number sequence from 1 to 5, students as a team on the counter dial beads. Highlights: dial a bead, and added a bead to be 2; the dial on the basis of 2 1 beads to get a 3 ... ... the card can also learn with similar operations (such as put flowers, First put one, and added one to get two; and added an a to be 3 ... ...), so that students come to understand the actual operation, followed by a number is added by the previous one obtained by a number .

put ideas and then let the students figure. Figure 5 basis points through the pendulum, so that students grasp the whole number of 1 to 5 of the order. Gracefully after question: interaction among students can answer each question.

4. Teaching Writing 1 to 5.

1 ~ 5 of the writing can be divided into two paragraphs, the first teaching of writing 1,2,3, 4,5 and then teaching writing. Teaching students to write numbers in the following general procedure.

(1) Teacher demonstration of each number is written first. Can be made of computer courseware, to where started to write, where to turn, where stopped writing demonstrates clear. And explain in writing each number in the grid layout.

(2) and then allowing students to carry out every word of stroke empty exercise book, or gestures on the table.

(3) Finally, let students practice in a book written description and Gerry.

the number of students began to practice writing, the teacher should pay attention to inspections, identify problems and to timely guidance, 1 to 5 in the 5 figures within a class of about 25 to 30 minutes to practice time, since we must pay attention often interspersed practice writing numbers.

5. Teaching

(1) compare the size of two numbers is learned in the previous method of using one to one based on the ratio of the number. To enable students to learn this part of knowledge, teachers should provide students with school pictures for operation: three monkeys, four pears, 3 peach, 2 bananas.

(2) teaching, let the students observe the topic map, map the same table to talk about the meaning of each other. Then teacher asked: a monkey eating a pear, a peach, a banana enough? how to swing, you can see at a glance? Fig.

teachers can also make the computer courseware, so that the monkey theme of the painting, pears, peaches and bananas jumped from the screen, put into, such as pictograms on page 17, and marked with numbers.

(3) Question: . The introduction of the textbook on page 17 in the And thinking through the operation, students understand: write

(4) A number Number of students in order to prevent confusion on the

in by 3> 2,3 <4, the findings, to guide students to think: order situation, to the order of 1 to 5, 3 2, the back, so 3> 2,3 and 4 in front, so 3 <4.

(5) Reflections on the 17th of textbooks is a problem than how much. Students to think There are several ways this problem. Such as: Some students with one to one method (connection with operations by learning) to see more rabbits, radishes, therefore, I have a rabbit could not get radish; number of students and some only a few rabbits out of 5, a radish number is 4, according to the order of 1 to 5 obtained 4 <5, so each rabbit eating a carrot is not enough.

(6) textbook on page 18, This is the first time between symbols Does not require students to write figures.

6. Teaching

natural numbers has two meanings, when used to indicate the number of things, called the base; used to indicate the order of things, it is called ordinal. This section is another means of teaching the natural numbers: ordinal meaning. Students understand the meaning of the base 1 to 5, based on the material through a common queue ticket plans, the introduction of ordinal meaning of teaching.

(1) teaching to guide students to look at pictures, to say who is ranked second, behind the children's uncle, the first few rows, the last row of the first few uncles and fill in the box the number of Figure meaning and filled by that number, the initial perception of the students, their number is filled, said

teachers can be made of computer courseware picture to expand the use of the drawing functions. Animation Show: Aunt in red have bought tickets to go (animated exit), the latter who in turn approached, then, the teacher asked: two uncles children behind it?

queue up shop, is a citizen should have the basic quality of teaching,

(2) To help students understand the meaning of ordinal numbers, teachers, students can also get things such as the number of students in the school playground on the runway, for example, to enable students to further understand the (3) the textbook on page 18, Enable students to see a This photo can also be used to raise questions about the meaning of cardinal and ordinal number of other issues. Such as:

7. Teaching

knowledge is composed of the number of the basis for learning addition and subtraction, to pay attention to this aspect of teaching. During this teaching, teaching materials to

(1) textbook topic on page 19 maps, teaching Under the guidance of teachers, students put saffron (you can also learn to use other tools instead of) Students talk about, how to divide, and the 4 into a few and several.

(2) teachers, the students divided the process and results summarized: 4 safflower, first move one to the right, indicating that 3 and a composition of 4; and then go down the right shift 1, 2, and note 2 composed of 4; finally go down to the right of a shift, indicating that components 1 and 3 4.

analytical writing:

then guide the students to compare:

enable students to understand these two points is the same method. Do not rote.

above process, the teacher can be made of computer courseware, animated sub-process and results.

(3) the textbook on page 19, In the guessing game for students to master the composition of 2,3,4. This activity in class, the game process, the result of guessing the number of Reclamation in the book. At the same table game between two students, teachers and all students can be together.

(4) the subject of the textbook on page 20 figure, teaching Teaching, so that each student prepare five small stick, the teacher asked: divide it into two piles, there are several points system? At this time no teacher to guide, to enable students to link 4 consisting of operation, as a team all hands, mutual inspiration, help, and then summed up as a team to 5 points into two piles of several different methods, and Fill this method several points in the book.

above process can be made of teachers, computer courseware, through animation showing the five small stick into the process and results of two piles, formed in the minds of students composed of 5 distinctive appearance, so that the memory of understanding 5 composition.

(5) guide the students to organize, to enable students to understand and, and is the same, as long as the composition of that 4 and 1 5 to 1 and 4 are composed of thought 5. Similarly, as long as the composition of that 2 and 3 5, then 3 and 2 are composed of 5.

(6) topic map following Activities, teachers produce labeled Example, some students produced three yellow discs and 2 red wafer; some students to produce digital card 3 and 2. Regardless of physical or students to produce the digital cards are correctly expressed the 5 composition, have been affirmed.

on the basis of the activity, so that the composition of 5 students to practice connection. First image can be composed of 5 lines to link the two piles, and then can be composed of 5 cards with two numbers together. Through this activity students to further understand the composition of 5, the law is a physical action with a gradual transition to the number of abstraction. Through this activity, to deepen understanding of the composition of the 5 and memory.

8. Second, some of the exercises on the practice of teaching suggestions.

(1) the first question is about the base of the meaning of 1,2,3 exercises. 3 questions to practice a different way. Question number 1 is the number of objects on the basis of the number of Reclamation; question 2 ways to use the connection number and the corresponding number of objects connected together; No. 3 coloring problem with the way that the number of how many. Practice, the first guide the students to read map views, and then requested operation.

(2) 4 sequence question is about the number of exercises, number of students according to the order of (cis number or last) number should be filled out several small flags, and then write out this number.

(3) 5,6 than the size of the problem is about the exercises. Be the first 5 questions, let students look at the map, count the number of objects in the diagram, and then in () in the fill number, then the meaning of number. Question 6 for students under the two numbers given to more than size, number in the

(4) Question 7 is about the activities of the meaning of ordinal questions. The two students learn at the same table with the card can be used to practice.

(5) Question 8 is composed of the number of exercises. After the students, teachers may ask: 10 questions is a comprehensive exercise. 9 questions for students to circle through the circle, painted several painting and other activities and a few distinguished. Question number 10 is the ratio of the number and size of these two points together the knowledge to practice.

newly enrolled children in the low levels of literacy, so the above exercises are map-based presentment. Students to practice, we must guide them to seriously look at pictures, read map views, and then write counts. Intended for students who can not read plans, teachers should be guided. 1. This section can be used 5 hours of instruction. An initial understanding of teaching addition and the addition of 1 to 5, an initial understanding of subtraction and subtraction from 1 to 5, and for the consolidation exercise in the classroom and integrated practice exercises in completing the exercises three.

2. The introduction of the addition, although very simple calculation, but it plays in the unit more important role. Giving students a preliminary understanding of the meaning of the addition will be calculated with the correct addition of 1 to 5. Therefore, we must attach importance to the teaching of this content.

(1) teaching, teachers can be the subject of page 23 made of computer courseware diagram, animation shows the two objects (or two groups) combined with the process. Such as: go first to a child, holding the hands of a red paper cranes, then came two children, held the hands of a blue paper cranes each, find the total number of paper cranes. Is to a blue-red paper cranes and two combined paper cranes (on the table), which is the number 1 and 2, the two together. Children as the material can also allow students to observe, go first to a child, then came two children, seeking a total number of children to make 1 and 2 together. Formula is 1 +2 = 3. Then teaching students knowledge plus the equal sign, tell the students to read law addition formula: 1 plus 2 equals 3, or 1 plus 2 was 3.

(2) To enable students to deepen their understanding of the meaning of addition. Teaching children the right hand through one of the three red balloons and left in a blue balloon combined activities, teaching 3 +1 = 4. This activity should allow every student to participate. Activity material can be replaced with a small stick, geometric images, pencil and other in-kind. If so that every child the right hand three pencil, take a left, find a total of many pencils, a pencil is to be combined in the hands, that is, add up to 3 and 1, written formula is 3 +1 = 4. Through the students experience the

(3) on page 23 in Two students at the same table with each other when the small teacher. Or as a team after the side put his mouth formula, represented stage presentation that formula. As much as possible to enable students to independently create and actively participate in the activities of way.

3. 4 +1 = 5 material to the calculation process, for example teaching the addition of 1 to 5.

(1) teaching, teachers must present an animation scenario: There are four birds, and flying one. After the students observe the question: , the teachers write the formula 4 +1 = 5. Ask: Teacher visits to understand the students in the class of several different algorithms, and then let them put their algorithm in the class display. Textbooks for students show there are three kinds of algorithms: one is with Deshu's. Actual teaching, the algorithm may be some students, despite their different way of thinking, thinking there is some level of difference, as long as the various algorithms have some truth, should be recognized.

display a variety of algorithms, may lead students to discuss: which of these algorithms is simpler? Initial understanding of the students learned to apply the number of previous knowledge to calculate the composition, more convenient.

(2) on page 24, 3 +2 = as calculated, the students at the pictures and ③ By comparing the 3 +2 = 5,2 +3 = 5 and 3 +3 = 4 +1 = 4,1 two of formula, so intuitive perception of the exchange students to the location of the two addends, and the same.

organize students to practice more, you can not meet the students only fill in a few years on the line. Can guide students to be observed, was whispering among the group or at the same table that the meaning of problems, question 1 can also be made into animated courseware to enable students to observe the meaning of the questions after that, and then calculate the counts. To enable more children to grasp the number of components used to calculate the knowledge of a level slightly higher level of thinking algorithm can ask: +2 = 5,2 +3 = 5 and 3 +1 = 4,bailey UGG boots,1 +3 = 4 when the two of formula, the formula can be used to make the following order animation:





so that students clearly see the similarities and differences between them, visually perceived exchange of position and change the two addends of the law.

4. Subtraction and addition of teaching the meaning of the teaching of thinking the same meaning.

(1) teaching the meaning of subtraction is addition to the meaning of teaching and learning activities. Teaching the subject on page 25 in addition to the meaning of map based on the activities, increase an activity: a child holding an origami crane from the table and left. Through this specific scenario, students think: Requires left several children, left a few paper cranes, which is removed from a 3, calculated by subtraction. Teaching, thematic maps can be made of courseware, animation showing the whole process. Give students a clear, remove one from the 3 inside, find a few left, we must subtract 1 from the 3 inside, written formula is 3-1 = 2. And teaching students understand the minus sign. Then, the read method of teaching formula: 3 minus 1 equals 2, or 3 minus 1 was 2.

(2) Teaching 4-2 = 2, the material has provided the Teachers can also design something similar for students to experience If there are 4 books on the table, Ding took the two, left two. Through these activities, to enable students to further clarify the meaning of subtraction.

(3) on page 25 in At the same table with each other when the school teacher.

5. Materials to 5-2 = 3 of the computing process, for example teaching subtraction from 1 to 5.

(1) teaching, teachers must present an animated scene: There are five apples, pack away the hedgehog 2. After the students observe the question: answers, teachers write the equation 5-2 = 3. Ask: Students say the algorithm is shown perhaps more than teaching the 3 kinds of algorithms we still need more, as long as reasonable, should be affirmed.

various algorithms show in class, teachers should actively guide students to compare the teaching process with the addition of teaching similar.

(2) on page 26, Exercise, students should understand the meaning of subtraction, the subtraction from 1 to 5, the calculation methods of understanding of the situation, and guide students to think, apply the method of contrast visual perception 5-1 = 4,5-4 = 1 and 4-1 = 3,4-3 = 1, the decreases in both of the formula and the difference in the relationship between the function of both the initial penetration of ideas.

6. Some exercises on the practice of teaching the three proposals.

practice is in line with the three exercises in addition and subtraction, and the meaning of 1 to 5 of addition and subtraction and design. With practice, students learn more about addition and subtraction understanding of the meaning will be correctly applied the method they are familiar with the composition of knowledge in particular to calculate the number of 1 to 5 of addition and subtraction. The practice of 11 questions in 6 (No. 1,4,5,8,9,11 questions) is to draw pictures to show the meaning of the questions, in order to enable students to understand the meaning of the 6 questions, according to local teachers conditions or activities into the computer courseware slide show for each question the activities of the dynamic process of the activities of students is based on real meaning of the questions and filling formula.

(1) the first problem is to recognize the addition of 1,4 meaning of practice. Exercise, let the students watch the animated picture, at the same table for two (or in small groups) to talk about plans agreed with each other, and then fill in the box number. The difference between two questions: Question 1 is given by the two addend Figure meaning only require students to fill thanks to a number; Section 4 gives an addend problem only for students under the plans and was intended to fill the other addend number.

(2) the first two levels of 2,3-addition problem is math. 2 questions for students to put a stick thanks to a number calculated on the basis of the first three questions from the students to think independently, with their own understanding of the way (preferably an integral number of knowledge) to fill counts.

(3) Section 5,8 subtraction problem is understanding the meaning of the practice. Practice method similar problems with the first 1,4. Teachers can guide students said map means. If Question 8: . Then fill the box in the formula number.

(4) the first two levels of 6,7 subtraction problem is math. Students practice question 6 should be first with Learning Tools (flowers, pictures or other local materials geometric objects) pendulum pendulum, and then say counts. 7 questions to enable students to think independently, with their own understanding of the way (preferably an integral number of knowledge) is calculated.

(5) Question 9 is the understanding of addition and subtraction means comprehensive practice. Guide students to operations, to enable students to understand the meaning of problems, based on the formula to write the number of the Chinese box. Through the addition and subtraction contrast the meaning of practice, deepen their addition, subtraction understanding of the meaning.

(6) 10 questions is 1 to 5 of addition and subtraction calculation of practice. Title in a total of 3 groups, each have an intuitive sense for students to add, subtract relationship. Let the students practicing independently, to fill out thanks to a number, then remove a group of any of them, such as the two left a group of formula allows students to compare, as a team to talk about the similarities and differences between them and the relationship between then represented in the class Free said. Initial perception of students addition and subtraction relationship.

(7) the first 11 questions is a game activities: sit in the car. Through this activity so that students can more skillfully calculated from 1 to 5 of addition and subtraction. Practice, the teacher should explain the rules of the game first students: Each card is a ticket, thanks to a number on the card in the box corresponding to the number of cars on the can on the car over. Several modalities are now available for selection: ① the connection method you use to tell you which car on Which the children? ② teachers posted on the board marked with a 1 5 5 5 digits of the car this picture, sent to nine children per Zhang tickets, each ticket above is a formula. (You can also prepare some more When the students did not get the tickets from the teachers, judges look at whether they are on the car. Allow students to practice in the game 1 to 5 of addition, subtraction calculations.

0 0 awareness and related addition and subtraction

1. This section can be 2 hours of instruction. Understanding of teaching and related 0 0 addition and subtraction, and the consolidation exercise in the classroom to complete the four exercises in the exercises.

2. 0 means no means of teaching, can be the monkey on page 29 made the process of computer courseware to eat peaches, peach show the number of changes from the 2-1-0 process: the plate with 2 peach, denoted by 2 ; monkey ate one, and then one, denoted by 1; after eating one plate number is 0, peach, recorded as 0, read as Through the above process shows that the initial perception of the students the meaning of 0, 0 and 1,2 to know as well as a number, not to zero represents.

then ruler materials produced map, which is speaking in front of the number of dots that chart the further improvement of the order. Figure by a ruler so that students become more familiar with the order number. Teaching so that each student bring their own ruler, the ruler of the left to find 0,UGG boots cheap, that 0 is the starting point. And then let the students talk about, a number 0 on the right a few, the last paragraph by paragraph count. Here are just a few recognize the order number and the master, not the understanding of meter stick, so do not speak the concept of equal length cm. 0

teaching writing, when students should note strokes, from top to bottom, left to right, started to write at the Department and the closing document to be connected, and to write smooth, not angular. Teaching students to practice the method can be found in front of the number of teaching writing teaching suggestions.

3. Materials from the nest by three birds flew in the picture thanks to a number of teaching subtraction is 0. Teaching, courseware can be made the picture: there are three birds nest, and then they reach the sky together. According to this scenario to explain 3-3 = 0. In order to enhance the students subtract the same number of results to understand the meaning of 0, teachers may design some activities. Such as: the teacher hands five stories, the whole book, she gave this 5 Xiao Ming, teachers and books? Formulation is 5-5 = 0.

4. For 0, addition and subtraction, two figures appear through the material ex 4 +0 and 5-0. Teaching, let the students observe the two frogs on a lotus leaf diagram, the same table to talk about each piece have a few frogs on a lotus leaf. Then ask: About 5-0, they should guide students to think independently,Bailey UGG boots, if a student can not think, teachers example, something from 5 years to remove 0, that is, did not get rid of one, so 5-0 = 5.

5. On page 29, Students done, 1 to 2 out of question can be considered reasonable to say, such as 0 +0 = 0, students should understand: what Canada 0 0 0 or something.

6. Some exercises on the practice of teaching four recommendations.

see question 1, there are a few goldfish bowl to fill a few figures, the first 3 months there are no goldfish bowl, fill the number 0. Problem 2 Review

number within the order of 5. Exercise, so that each student put on the table Yi Bai. So that students can test how the number of master sequence to see if that should be placed in a 0 in front.