Number pair is a concept of position, which is equivalent to coordinates. The former number represents a column and the latter number represents a row. For example, (2,5) means that its position is the fifth row of the second column. You can easily locate a place. Look first, then look.

Paired counting was invented by Descartes. Once, he was sick, lying in bed, and found a spider in the corner. Descartes begins with the position of the spider, and is marked as (0,0). Several pairs are used to represent all the intersections on the spider's web.

Extended data

The meaning of correlation number pair when determining the position of an object;

(1) The first number indicates which column the object is in, generally counting from left to right; The second number indicates which line the object is in, usually counting backwards.

(2) When writing number pairs, write the number of columns first, and then write the number of rows.

Number pairs can describe the position of an object on a plane, which has the same function as coordinates in a coordinate system, and are both positioning. But it cannot be called a coordinate system. A coordinate system should have three elements, namely coordinate origin, unit length and direction. If (0,0) is defined as the coordinate origin, the number pair has the same function as the coordinate system.

Baidu Encyclopedia-Digital Pair