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 -axis is also called the first axis, while the -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.
Think About This
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
Read the Coordinates of a Point
- 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: . 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.
Think About This
Can you read the coordinates of the different points above?
Math Vault
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