In mathematics, the middle point usually represents an interval, a range of numbers, and can also be used to indicate the difference between two numbers. In algebra, the plus sign in the middle can represent an unknown number. For example, when calculating the coordinates of the midpoint between two points, (x 1+x2)/2 is used to indicate the position of the middle plus sign.

In geometry, adding points in the middle also plays an important role. For example, if we want to prove the bisector theorem of a triangle, we need to draw a midpoint on one side of the triangle to better express the meaning of the theorem. In addition, the middle point can also be used to represent the relationship between parallel lines, such as the bisector of the diagonal in a parallelogram.

In statistics, the middle point is usually used to represent the data changes in statistical information. For example, if we want to describe the median value of a data set, we can divide the data in the data set into two parts with the plus sign in the middle, and then find the median value. In addition, the middle point can also be used to represent the standard deviation of the sample, which helps us to better understand the data distribution.