Why Coordinates

First identify the fixed starting point. Next identify the two directions used. Then write the position as an ordered pair without interchanging the numbers.

A simple classroom seating grid or graph paper grid can show how row and column together identify one exact position.

Writing only 4 for row 4, column 2 is incomplete because it does not tell the column.

Coordinates are numbers used to locate the exact position of a point with respect to a fixed reference line or fixed axes.

Coordinates are numbers used to locate the exact position of a point with respect to a fixed reference line or fixed axes. On a line, one coordinate can locate a point. On a plane, an ordered pair (x, y) locates a point uniquely. If a student sits in row 3 and column 5, the pair (3, 5) helps locate the seat uniquely.

In daily life, position becomes clear only when we use a reference. A seat number in a cinema hall, a row and column in a classroom, or a point on graph paper works because there is a fixed starting point and a fixed direction. Coordinates give the same clarity in mathematics. On a line, one coordinate can locate a point. On a plane, an ordered pair (x, y) locates a point uniquely. A classroom has 6 rows and 5 columns. A student at row 4 and column 2 is written as (4, 2). Changing it to (2, 4) usually means a different seat, so order matters. Students may be asked why a single number is enough on a number line but an ordered pair is needed on a plane. Writing only 4 for row 4, column 2 is incomplete because it does not tell the column.