Knowledge points of mathematics practice in the first volume of the fourth grade
Fill in the blanks.
1. The quadrangles we have studied are (), (), () and ().
2. When two straight lines intersect at () degrees, the two straight lines are perpendicular to each other.
3, parallelogram has ().
4. Two adjacent sides of a rectangle are mutually (). The two opposite faces are mutual ().
5. With one side of the parallelogram as the base, () heights can be made, and the lengths of these heights are all ().
6. In the same plane, two straight lines of () are called parallel lines.
7, () and () are special parallelograms.
8, isosceles trapezoid () A group of opposite sides are parallel.
9, parallelogram () axisymmetric graphics.
10, the sum of the internal angles of any quadrilateral is () degrees.
Second, choose.
1, from a point on one side of the parallelogram to the opposite side, you can draw a vertical line ().
One a, one b, two c, countless.
2. Two identical triangles can be spelled into one ().
A, parallelogram b, trapezoid c, rectangle
3. In the figure below, the one that is not axisymmetric is ().
A, rectangle b, circle c, parallelogram d, isosceles trapezoid
4. There are () groups of parallel sides in the rectangle.
a、 1 B、2 C、4
Third, the judge.
1, two trapezoids can be combined into a parallelogram. ( )
2. A figure with four right angles must be a rectangle. ( )
You can draw a straight line after a while. ( )
4. A quadrilateral with only one set of parallel opposite sides must be a trapezoid. ( )
As long as they don't intersect, they must be parallel lines. ( )
6. When two straight lines intersect, they must be vertical. ( )
Knowledge points of "angle measurement" in the first volume of fourth grade mathematics
1. Line, light, angle
Straight line: a line that extends infinitely to both ends and has no end.
Ray: it can be like a line extending in one direction, and the ray has an endpoint.
Line segment: a line that cannot be extended. A line segment has two endpoints.
Angle:
A figure composed of two rays with a common endpoint is called an angle.
This common endpoint is called the vertex of the angle, and these two rays are called the two sides of the angle.
2. The connection and difference between straight lines, rays and line segments.
1) Both lines and rays can extend indefinitely, so the length cannot be measured.
2) The length of the line segment can be measured.
3) A line segment has two endpoints, a straight line has no endpoint, and a ray has only one endpoint.
3. The characteristics of angle
A corner has a vertex and two sides.
The angle is usually represented by the symbol "∞"
4. Angle size comparison:
The unit of measurement of angle is "degree", and the symbol is "degree". The semicircle is divided into 180 equal parts, and the angle of each equal part is l degrees. Record it as 1, and measure the angle with a protractor.
Learning methods of Olympic mathematics in the fourth grade of primary school
1, grab the classroom. Mathematics study focuses on weekdays and is not suitable for surprise review. The most important thing to study on weekdays is to attend class for 40 minutes. Listen attentively and keep your thoughts close to the teacher. At the same time, it should be pointed out that many students tend to ignore the mathematical ideas and methods taught by teachers and pay attention to the answers to questions. In fact, the way of thinking is far more important than the answers to some questions.
2. Complete the homework with high quality. The so-called high quality refers to high precision and high speed. When writing homework, I sometimes repeat the same type of questions. At this time, we should consciously examine the speed and accuracy, and we can have a deeper thinking about this kind of problem every time we finish it, such as the content it examines, the mathematical thinking method used, the rules and skills of solving problems, etc. In addition, the thinking questions assigned by the teacher should also be carefully completed. If you don't give up easily, you must carry forward the spirit of "nails" and think quietly whenever you have time. Inspiration always pops up in front of you. Most importantly, this is an opportunity to challenge yourself. Success will bring self-confidence, which is very important for learning mathematics; Even if you fail, this question will leave a deep impression on you.
3. Think hard and ask more questions. First of all, for the concepts and laws given by teachers, we should not only know "why", but also know "why" and get to the bottom of it. This is the way to understand. Secondly, we should be skeptical about learning any subject, especially mathematics. If you have any questions about the teacher's explanation and the content of the textbook, please feel free to ask questions and discuss with the teacher. In a word, thinking and asking questions are the ways to eliminate hidden dangers in learning.
4. Summarize and compare, and clear your mind.
(1) summary and comparison of knowledge points. After learning a unit, you should sort out the contents of this chapter or go through it in your mind to clarify the relationship between them. Similar and confusing knowledge points should be summarized and compared separately, and sometimes they can be distinguished by association.
(2) Summary and comparison of topics. Students can set up their own question bank. I have two sets of problem sets. One is wrong and the other is accurate. Write down the mistakes in the usual homework and exams selectively, and mark the matters needing attention with a red pen on one side. Just read what is written in red pen before the exam. I also wrote down some extremely clever or difficult problems I saw, and marked the methods and ideas used in this problem with a red pen. After a long time, I can sum up some types of problem-solving rules and write them down in red notes. In the end, they will become your precious wealth and be of great help to your math study.
5. Do extracurricular exercises seriously. Spare time is very precious to our primary school students, so you should be accurate and precise when you do extracurricular exercises. As long as you do three or two pages carefully every day, your math study will be "a tower of sand" and fruitful.
Related articles on the induction of important knowledge points of mathematics in grade four;
★ Summarize the knowledge points of the first volume of mathematics in the fourth grade of primary school.
★ Knowledge points in the first volume of fourth grade mathematics
★ Summarize the knowledge points of mathematics in the first volume of the fourth grade.
★ Summary of knowledge points for final review of fourth grade mathematics in Jiangsu Education Edition
★ Summarize the knowledge points of the fourth grade mathematical triangle.
★ Guidance of mathematics learning methods in the fourth grade of primary school
★ Important knowledge points in the first volume of mathematics in the fourth grade of primary school
★ Summary of knowledge points in the second volume of fourth grade mathematics
★ Review materials of mathematics knowledge points in the second volume of the fourth grade of primary school.
★ Summary of Mathematics Learning Methods in Grade Four of Primary School