Knowledge and skills:
(1) Understand the meaning of multiplication in a specific situation, know the multiplication sign, and know the names of each part in the multiplication formula.
(2) Memorize the multiplication formula of 26 and skillfully calculate the multiplication of two numbers within 6.
Process and method:
(1) Let students experience the operational significance of multiplication in specific situations.
(2) Let students go through the compiling process of multiplication formula, and in the process of exploring the formula memory method, form the preliminary reasoning ability.
Emotions, attitudes and values;
(1) In combination with teaching, educate students to love learning and labor, and cultivate students' good study habits such as careful observation and independent thinking.
(2) Feel the close relationship between mathematics and life, and enhance the confidence in learning mathematics.
(3) Cultivate students' reasoning ability and thinking agility.
Emphasis and difficulty in teaching
Key points: Understand the meaning of multiplication, and rewrite the same addend into multiplication formula.
Difficulty: Understand the meaning of multiplication.
teaching tool
courseware
teaching process
1. scene import
Teacher: Students, do you like going to the playground? Have you ever played with your parents in the park? What recreational activities have you participated in?
Bumper cars, water cruises, monkeys climbing trees.
Show the playground in the courseware
There are many math problems on the playground. Have you seen them?
Health 1: I have seen small trains and bumper cars.
Health 2: There are 20 people who have played the small train.
Health 3: There are also 8 people in the bumper car.
Teacher: How do you know?
Health 2: I do the math.
Health 3: I did the math.
Blackboard: 2+2+2+2=8
Today we are going to learn how to calculate by multiplication.
Explore new knowledge
Learn the example 1( 1) on page 47.
Ask questions:
A, do you all know how many people are on the plane? How did you work it out? Group discussion.
B communication report: just use the number; 3+3+3+3+3= 15 for addition calculation.
What are the characteristics of this formula C? Who knows? Group cooperation * * * with discussion.
This problem is easy for most students to see, but there are also some students with poor understanding ability in the class, so any problem should be easy first and then difficult.
Report: Every addend is the same.
Learn the example 1(2) on page 47.
Show sample pictures in the courseware.
Students, do you all know how many people are on the small train? How did you work it out? Group discussion.
B communication report: just use the number; 4+4+4+4=20 for addition calculation.
What are the characteristics of this formula C? Who knows? Group cooperation * * * with discussion.
Report: Every addend is the same.
Learn the example 1(3) on page 47.
According to the above, please teach yourself this example.
Report: 2+2+2+2+2 =14.
Summary: This addition with the same addend can also be expressed by multiplication.
Multiplication formula: 2? 7= 14 or 7? 2= 14
Teacher: We have learned plus and minus signs before. Is this tilted left and right? This is called multiplication.
Question: Who can write the above addition formula into multiplication formula? Who will challenge?
Teacher: Do you know how to pronounce multiplication formula?
Answer by name, teachers and students correct me.
2? 7= 14 Pronunciation: 2 times 7 equals 14. 7? 2= 14 Pronunciation: 7 times 2 equals 14.
3. Teaching? 2? 7= 14? Meaning of.
Discuss the significance of multiplication in groups.
Report the results.
The teacher concluded:? 2? Represents the same addend. 7? Represents the number of the same addend. 14? Represents the sum of the same addend. Seven twos can be written as two? 7= 14, which can also be written as 7? 2= 14, which is the addition of 7 2.
Discussion: What if you add 2, such as 8, 12?
Learn Example 2 on page 48.
Teacher: Do the students know the names of the numbers in the multiplication formula?
5+5+5= 15
5? 3= 15
3? 5= 15
3 and 5 are both called. Multiplier? ,? It's called multiplication 15? This is called a product
4. Classroom exercises.
Do 48 pages independently, but you will report and communicate, and the teachers will correct them.
5. Expansion and upgrade.
Addition formula: _ _ _ _ _ _ _
Multiplication formula: _ _ or _ _
B. Complete 1, 2, 3 of Exercise 9 independently.
Summary after class
Ask questions:
What did you learn in this class?
Teacher-student summary:
It is very simple to find the sum of several identical addends by multiplication.
B left oblique right oblique? This is called multiplication.
C The first multiplier represents the same addend, the second multiplier represents the number of the same addend, and the number after the equal sign represents the sum of the same addend. Such as: 2? 7= 14, 7 twos can be written as 2? 7= 14, which can also be written as 7? 2= 14, which is the addition of 7 2.
Write on the blackboard.
A preliminary understanding of multiplication
Addition with the same addend is easier to be represented by multiplication.
5 3 3+3+3+3+3= 15 5? 3= 15 3? 5= 15
Seven 2 2+2+2+2+2+2+2+2 = 14 7? 2= 14 2? 4= 14
2? 7= 14 Pronunciation: 2 times 7 equals 14.
7? 2= 14 Pronunciation: 7 times 2 equals 14.
5+5+5= 15
5? 3= 15
3? 5= 15
"Preliminary Understanding of Multiplication" Teaching Plan (2) Teaching Objectives
Knowledge goal: let students experience the creation process of multiplication in a simple form of adding several identical addends, and get a preliminary understanding of the significance of multiplication and the relationship and difference between multiplication and addition. Can read and write multiplication formula correctly.
Ability goal: Let students abstract how many mathematical problems to add from simple practical problems, cultivate the habit of thinking about problems in an orderly way and improve their ability to solve problems in the activities of multiplication according to mathematical problems.
Emotional goal: In the teaching of the preliminary understanding and application of multiplication, let students continue to cultivate their interest in mathematics and cooperative learning attitude.
Emphasis and difficulty in teaching
Teaching emphasis: establish the concept of multiplication, understand the meaning of multiplication formula, and rewrite the multiplication formula by adding the same addend.
Teaching difficulties: understand the meaning of multiplication, understand the different meanings of two numbers before and after multiplication, and identify the same addend.
teaching tool
Ppt courseware
teaching process
First, contact life and introduce situations.
1. Teacher-student dialogue, which leads to the playground and shows the scene map.
Students, where did you go to play during the National Day holiday? Who will say something?
Students, some children used their holidays to go to the playground. They had a good time. do you want to see it ? Ok, let's have a look. ) courseware shows the amusement scene map.
2. Students, some children are playing the Ferris wheel, some children are playing the roller coaster, and some children are playing the train. Let's look at the children who play on the roller coaster first: every two children on the roller coaster ride in a carriage, and students watch (courseware demonstration: circle the children on the roller coaster with red circles. ) Let's count two by two (teachers and students * * *). How many twos did we count? How to express it by addition formula? Blackboard book: 2+2+2+2 =12 (how many 2s are there in total? How many children are there in six twos? )
3. Let's look at the children playing on the Ferris wheel again: every four children sit in a hanging box on the Ferris wheel, and students watch (courseware demonstration: circle the four children on the Ferris wheel with red circles. ) Let's count four together (teachers and students * * *). How many fours did we count? How to express it by addition formula? Blackboard: 4+4+4 = 20 (how many 4' s are there in total? How many children are there in five fours? )
4. Let's look at the next friend who plays a small train: every three people on the small train sit in a carriage, and the students watch (courseware demonstration: circle the three children on the small train with red circles. ) Let's count three threes together (teacher and student * * *). How many threes did we count? How to express it by addition formula? Blackboard: 3+3+3 = 12 (while writing on the blackboard, ask: How much does 3 add up to? How many people are there in four threes? )
Second, explore independently and know how to multiply.
1. Observe all the written formulas and inspire students to discover the characteristics of the same addend formula.
Students, it's amazing that we solved some math problems on the playground. Please follow these formulas we wrote. What did you find? Students will give different opinions. If students can't find the features, the teacher can guide them: What is each addend in the first formula? The second formula, the third formula, what is each addend? ) Teacher's summary: The addends in each formula are the same. )
Summary: In this formula, each addend is the same, and they are all the same. We call it addend:? Same addend? (blackboard writing), adding the same addend formula like this, we can simply say? How much does it add up to? .
2. Ask students to find the same addend in each formula.
3. Guide students to use several numbers to represent the addition formula of the same addend.
Who is the same addend in the first formula? How many twos add up? How many identical addends does the second formula have? Who is the same addend? So how many times does this formula add up? What is the third formula? Q: What is the same addend? (Let's count together) What does three add up to?
4. Thinking caused by confusion.
Guide the students to observe six 2- addition formulas: Students, these are six 2- addition formulas. If there are 100 twos, how to write the addition formula? (Students may say add up 100 two. ) Imagine adding up 100 twos. What would it look like to write it out?
So do we have a simpler way to express such an addition formula with the same addend? Can you express this addition formula in a simpler way? (The formula here is: 2+2+2+2 =12).
Think about it and communicate with each other at the same table.
The way students communicate, say the name of the blackboard. (Encourage reasonable methods) If students can write multiplication formula 6? 2 or 2? 6. The teacher gave encouragement and praise: You are really amazing, just as mathematicians think, mathematicians say.
If the students can't say it, the teacher directly tells the students: six twos add up, you can also express it like this: 6? 2= 12 (blackboard writing)
5. Reveal the topic, follow the study and guide (understand the meaning of multiplication and know multiplication)
This is a new method, multiplication. In this lesson, we will learn: the preliminary understanding of multiplication (blackboard writing topic).
Six two add up, can we use six? 2= 12, so what does 6 mean here? What does this mean? What do they have to do with the original addition formula? (Look at the addition formula, think about it and say it)
Summary: Yes, 2 is the same addend in the original addition formula. 6 means there are six 2s, that is, the number of 2s. What does this formula mean? This formula means the addition of six twos (the teacher points to the blackboard in front? Six twos add up? E.g.)
Who can tell the teacher what this formula means again? (More students say)
The addition of six twos can also be expressed as: 2? 6= 12
What does 2 mean here? What does 6 mean? What does this formula mean? Who will tell me what this formula means again? )
Summary: 2 in these two formulas both represent the same addend 2. In the original addition formula, 6 in these two formulas both represent the number of the same addend 2, and there are 6 2s, which all represent the addition of 6 2s (the teacher pointed to the blackboard in front? Six twos add up? E.g.)
What is the symbol between these two formulas? Who knows? (blackboard writing: multiplication sign)
What is the multiplication sign like?
Summary: multiplication and addition are closely related, and multiplication is obtained by addition in this way. Therefore, mathematicians have created a new sign multiplier by tilting the plus sign.
How to pronounce multiplication sign? Read a word while reading? By who? , this formula (6? 2= 12) How to read it? Who will give it a try? (Blackboard: 6 times 2 equals 12)
The second formula (2? 6= 12) How to read it? Who will give it a try? (blackboard writing: 2 times 6 equals 12)
Attention, students: multiplication sign only reads one word? By who? Read these two formulas together.
Look, students, what does it feel like to express such addition by multiplication?
Summary: Yes, it is very simple to express such an addition formula with the same addend by multiplication. In other words, it is easier to find the sum of several identical addends by multiplication.
6. Encourage students to rewrite several other addition formulas into multiplication formulas to understand students' learning situation. Provide students with personalized learning space and consolidate what they have learned.
Can you rewrite several other addition formulas on the blackboard into multiplication formulas? Communicate the students' learning results and ask them to say what the factors in each formula mean. What does the formula mean? )
The teacher once again stressed that it is very simple to calculate the formula of adding the same addend by multiplication like this. (blackboard writing: simple)
Third, simple application, forming ability
1. Consolidation exercise
Step 2 break through the game
Fourth, reflect and review, sum up the harvest: classmates, are you happy in this class? Think about what you have learned in this class. What have you gained?