1, understand that ten billion is the unit of counting,100000 is one million,10100000 is ten million,10100000 is one hundred million. Every four digits are one level, and the series between every two adjacent digits is 10. As long as you can fill in the following numerical sequence table accurately and answer three small questions correctly, it means that you have mastered the point of 1.
2. 1 hectare = 10000 square meters; 1km2 =1million m2 = 100 hectares.
3. Understand the difference between line segments, straight lines and rays, and understand how big right angles, right angles and rounded corners are. At the same time, we should know that an angle has a vertex and two sides. We will compare the size of the angle and measure the degree of the angle with a protractor.
3. Multiply three digits by two digits. This part is the key point. Students should be able to calculate the results vertically, and also know a rule, that is, one factor is constant, another factor is multiplied or divided by a few, and the product is also multiplied or divided by a few.
4. To learn this part of mathematics knowledge, we must first understand what is parallel-they don't intersect on the same plane. Also know what is vertical-two straight lines intersect at right angles, which is called perpendicular to each other. Finally, what is the base of the parallelogram? What is height?