A preliminary understanding of angle

Through children's observation of some electrical appliances in daily life, it is found that the "horn" is "sharp" and "horn has two straight sides." So we can get the definition of an angle: an angle is a figure consisting of a vertex and two sides.

Preliminary knowledge points of math corner in grade two

1, cognitive perspective

Features of an angle: a vertex and two sides (straight).

The size of the angle: it is related to the size of both sides, and has nothing to do with the length of both sides.

Angle drawing: fixing vertices. Draw a straight line from this point. Draw another side (at right angles, aim at the drawn side with the right angle, and draw a line along the other right angle).

2. Classification of angles

Understanding right angle: the characteristics of right angle; Understand acute angle and obtuse angle: acute angle is less than right angle, obtuse angle is greater than right angle; You can judge right angles, acute angles and obtuse angles with a triangular ruler: overlap the vertex of right angles on the triangular ruler with the vertex of the angle to be compared, then overlap one side of right angles on the triangular ruler with one side of the angle to be compared, and finally compare the other side of right angles on the triangular ruler with the other side of the angle to be compared. The right angles are on a straight line, including acute angles and obtuse angles.

A preliminary understanding of the teaching plan of mathematics corner in grade two

1, learning guidance target

Let the students know the angle, judge the angle and know the names of each part of the angle by combining the life situation and operation activities. Through learning, I understand that the angle is related to the size of the edge opening, but not to the length of the edge. I first learned to draw angles with a ruler. Cultivate students' practical ability and realize that mathematics comes from practice and the spirit of unity and cooperation.

2. Learning guidance points

Know the angle, know the names of each part of the angle, and learn to draw the angle with a ruler.

3. Difficulties in learning guidance

It is preliminarily recognized that the angle is related to the size of the openings on both sides, but not to the length of the sides.

4. Teaching objectives

Make students know the angle according to their life situation, know the names of each part of the angle, correctly point out the angle of the object surface and identify the angle in the plane figure. Through observation and operation, let students realize that the angle has a size, and can intuitively distinguish the size of the angle.

In the process of understanding the angle, students can experience the close relationship between mathematics and life, enhance their practical ability and improve their interest in learning mathematics.

5. Teaching emphases and difficulties

Teaching emphasis: Understand the angle initially and know the names of each part of the angle. Teaching difficulty: Make an active angle and realize that the angle is related to the divergence between the two sides.