Teaching design of "Who has more red fruits", the second volume of mathematics for the first grade of primary school published by Beijing Normal University.

Learning objectives:

1. Further understand the meaning and order of numbers in 100, and compare the sizes of numbers in 100.

2. Further accumulate experience in comparing numbers and cultivate a sense of numbers.

Teaching focus:

Compare the size of numbers in 100.

Teaching difficulties:

Master the method of comparing the size of numbers.

Teaching process:

First, review and pave the way to stimulate the introduction of interest

1, (1) 10 decimal is ()

(2) The number consisting of eight tens and five ones is ()

There are () ten and () one in 48.

(4) Counting from right to left on the counter, the first digit is (), the second digit is (), and the third digit is ().

(5) The unit of 21is (), which means () a one; Ten digits is (), indicating () ten digits.

2. Guessing games stimulate interest

The teacher first put forward the rules of the game: no numbers, only big or small.

Choose a student to write a number less than 20 on the blackboard, and another student will guess the number with his back to the blackboard. )

Please help him indicate whether it is big or small.

Second, create situations and explore new knowledge.

1. Perceive the size of two numbers under certain circumstances.

The little monkey and the little bear think that the children in our class are very clever and often help them solve problems. Look at this picture. What mathematical information do you find?

(Blackboard: Xiong 2 1 Little Monkey 18)

Teacher: What math questions can you ask from these two pieces of information?

Teacher: Today we are going to solve the problem of "who has more red fruits". (blackboard writing topic)

2. How to compare who gets more red fruits?

How to compare the size of 2 1 and 18? Do you have any good ideas?

3. Students think independently and communicate.

When students communicate, they may find the following ways:

Method 1: Compare numbers in sequence. (According to the numerical order within 100, from the beginning to the end. Count 18 first, and then three numbers are 2 1, so 2 1 is greater than 18,21~18).

Method 2: physical model comparison. Put a square instead of a red fruit and compare it. It is found that 2 1 square is three more than 18 square, so 2 1 ~ 18.

Method 3: Compare with the middle number. (2 1 is greater than 20 and 18 is less than 20, so 2 1 is greater than 18, that is, 2 1 ~ 18).

Method 4: Compare with the counter. (Dial the numbers 2 1 and 18 on the counter first, and then compare them on the counter: there are two beads on the tenth number of 2 1, which means that there is a bead on the tenth number of 18, indicating that 1 10 digits, and the two tens are greater than/kloc.

Method 5: Compare the composition of numbers. (2 1 the tenth place is 2, which means two tens, and 18 the tenth place is 1, which means 1 tens, and two tens are greater than 1 tens, so 2 1 is greater than1.

The teacher evaluates and summarizes the students' answers.

3. Explore the method of 32 and 34 yards.

Teacher: Students are really capable! The comparison method of these two numbers has been explored so fast, but the wise old man is still unconvinced and doesn't believe that you can explore so fast, so two more problems appear.

Students think independently and say the comparative method.

The teacher concluded: when ten people are the same, we compare the rankings. Three digits are greater than two digits and so on.

Third, feedback exercises.

1 test you. (courseware)

Fill in ">", "

48( )45 62( )75

59( )59 57( )56

80( )90 98( )89

Draw two or three sentences for students to say the comparison method.

2. Put the following figures in the correct position.

58 98 60 36 79

> > > >