1, the distance between two points on the number axis is the absolute value of the coordinate difference corresponding to these two points, that is, the difference between the number on the right and the number on the left MINUS. That is, the distance between two points on the number axis = the number represented by the right point-the number represented by the left point.

2. When a point moves on the number axis, because the right direction of the number axis is positive, the speed of moving to the right is regarded as positive speed, and the speed of moving to the right is regarded as negative speed. In this way, the coordinates of the point after moving can be directly obtained by adding the moving distance of the point on the basis of the starting point. That is, the number represented by point A is A, and the number represented by the left shift of unit B is A-B; After moving unit b to the right, the number is a+B.

3. The number axis is the product of the combination of numbers and shapes, and the motion analysis of points on the number axis should be combined with graphics. The path formed by the movement of points on the number axis can be regarded as the sum and difference relationship of line segments on the number axis.

What is the fixed-point problem?

The fixed point problem is to give one or more variables according to the moving point, line segment, angle change and area of a graph, and determine other relations between variables and other quantities, or to solve such problems by related calculations and comprehensive answers under certain conditions. Generally, it is necessary to classify and solve different situations according to the movement of points and the changing process of graphics.