1, inverse multiplication formula 1-7.
I said give an example: 6×7=
3, driving a train, the teacher said that the students answered.
4. Check each other's backs in pairs.
5. Change the formula.
Change the teacher's formula into an expression.
Example: 6742 students: 6×7=42 7×6=42.
Second, new funding.
1, Teacher: Read a story first (Snow White)
Teacher: How many fruits does Yi * * * have?
Health: 372 1, 2 1.
Teacher: Tell me about the math information in it.
Health: One * * * has seven dwarfs, and each dwarf has three fruits. How much fruit does a * * * have?
Teacher: Then how to write with expressions? Let's talk about addition first
Health: 3+3+3+3+3 = 21(piece) (blackboard writing)
Teacher: These are some 3s. What is the multiplication formula used?
Health: Seven threes, three seven two one.
Teacher: The multiplication formula is 3×7=2 1 (one).
Although the multiplication formula is relatively simple, we must first think clearly about the relationship inside.
2. Then look at the short man's plate in the picture. What is the mathematical information?
Health: There are hamburgers and French fries.
Teacher: OK, exactly.
Health: There are two hamburgers on each dwarf's plate.
Teacher: OK, there are two hamburgers on each dwarf's plate. How many hamburgers do the seven dwarfs have? How to write an expression?
Health: 2×7= 14 (unit)
Teacher: What about French fries?
Health: 7×7=49 (unit)
Teacher: What multiplication formula do they use?
Health: 277749
Teacher: OK, what else can you find?
Health: How many cups, flowers? ...
Teacher: OK, look at these formulas. We all use multiplication formula (blackboard formula).
In this way, all operations related to 7 use the multiplication formula of 7.
Third, practice.
1, practice
The first question:
Teacher: Who can read the questions completely and accurately?
Health: (reading)
Teacher: How much did you use that * *?
Student: With the multiplication formula, look at the horizontal bar first, and then look at the vertical bar.
Teacher: There are several columns and rows. Where's the formula?
Health: 4×7=28 (block)
The second and third questions (driving a train)
Look at the questions first, and then let your classmates answer them.
2. Practice in the book
Write by yourself-check-check 1 and 2 questions-choose students to tell the answers.
Step 3 extend
Teacher: So, let's see if the students have thought of it. Can a multiplication formula write two division formulas? give it a try
4, thinking: don't make any noise, think about what it means-the teacher will explain the topic-do it yourself-do a good job of finding the teacher's answer.
Viewpoint:
The summary link is: review-import-look at pictures and do information-formula-addition-multiplication-kill three birds with one stone-summary and topic introduction-practice.
The whole is complete, and the classroom effect is very good, but it is best to try more when giving examples.