# What Is a Coordinate System?

A coordinate system is a grid that is formed by two number lines crossing each other at the point where the number zero appears on both lines. This intersection is called the origin. A coordinate system looks like this:

The $x$-axis is also called the first axis, while the $y$-axis is called the the second axis.

You will come across coordinate systems both in math at school and in daily life. Coordinate systems are a tool that help you know where things are located.

Look at the coordinate system with the positive numbers on the figure. How do you think you read a point in the grid?

The answer is revealed further down on the page.

A point in the grid is called a coordinate. Every coordinate consists of one value from the first axis and one value from the second axis (see figure).

Below, you can see a coordinate system with points.These points are named after letters in the alphabet. This is how you find the coordinates of a point:

Rule

1.
Put your finger on the point, then drag your finger straight down until you hit the first axis. Write down the number that is now under your finger.
2.
Put your finger back on the point, then drag your finger straight left until you hit the second axis. Write down the number that is now under your finger.
3.
The coordinates should look like this: $\left(x,y\right)$. You have to replace the x with the number you found on the first axis. You have to replace the y with the number you found on the second axis.

Can you read the coordinates of the different points above?

 $A=\left(1,1\right)$ $B=\left(3,1\right)$ $C=\left(2,3\right)$ $D=\left(4,3\right)$ $E=\left(1,5\right)$ $F=\left(3,10\right)$ $G=\left(8,7\right)$ $H=\left(5,7\right)$ $I=\left(7,4\right)$ $J=\left(7,7\right)$ $K=\left(0,4\right)$ $L=\left(6,0\right)$
 $A=\left(1,1\right)$ $B=\left(3,1\right)$ $C=\left(2,3\right)$ $D=\left(4,3\right)$ $E=\left(1,5\right)$ $F=\left(3,10\right)$ $G=\left(8,7\right)$ $H=\left(5,7\right)$ $I=\left(7,4\right)$ $J=\left(7,7\right)$ $K=\left(0,4\right)$ $L=\left(6,0\right)$

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