1, the distance between two points on the number axis can be expressed as an absolute value, that is, the absolute value of the difference of numbers represented by two points. ?

2. The letter representation of a moving point on the number axis can be solved by addition or subtraction of rational numbers, that is, the number represented by the starting point adds or subtracts the moving distance of the moving point, plus in the positive direction and minus in the negative direction.

3. Find the midpoint of the line segment between any two points on the number axis, and divide the sum of the numbers represented by these two points by 2. If the points on the number axis represent numbers A and B, the midpoint of the line segment AB represents numbers of (a+b)/2.

4. 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 is subtracted. 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.

5. 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.