How much) is calculated by subtraction.

2

Be able to solve practical problems in life by exploring methods and cultivate them in the process of solving problems.

Interest in learning mathematics and consciousness of applying mathematics.

Teaching emphases and difficulties

Through intuitive placement, this paper leads to the exploration of new problem-solving methods and lists the subtraction formula for finding the difference between two numbers.

study

travel

set up

count

guide

navigate by water/air

plan

leave out

First, reveal the topic, clear objectives

1

The two children at the same table are heavily in debt.

Huang caught a handful of flowers in the school box. Guess.

Guess how many flowers the deskmate caught, and then put yourself

Tell your deskmate about the flowers you caught. Compare it. Who is it?

Catch a lot.

2

Look at the pictures and ask questions.

Second, goal-driven, autonomous learning

1.

Students solve problems by forming a line.

Think about it: What are the extra flowers?

extra

five

How did you get a flower?

what's up

2.

Game activity, merging algorithm.

Grab some children at the same table and compare them. Look at that.

Whoever catches more will catch more. Every time I catch it,

Talk to each other about how to count as a flower.

1.

Let's see who has bigger hands.

After fishing, let's see who catches more.

2

Show the wall chart and ask questions.

Dialogue: Xiaohong and Xiaoming also played a flower catching game. (Showing a wall chart) From the picture,

What materials did you read? What problem can you solve?

(1)

How much did they catch in a * * *

A flower?

B

Who caught more flowers and how much?

)

3.

Today, in this class, let's solve "which kinds are more?" How much more? "This question.

1.

Question: Do you have any way to know how much more red flowers are than blue flowers?

If the teacher has a lot of flowers, we also solve the problem in rows.

Is it convenient? Think about it. Is there any other way?

2.

Designated children report activities,

Let's talk about which flower has more flowers.

How many more,

Say again what flower has less fragments and how much is missing.

3.

Show the flip chart and ask questions:

What information did you read from the picture? What problems should be solved?

Communicate with each other at the same table

Show the questions raised by the students:

A

How many more girls than boys?

B

How many boys are less than girls?