Coordinates

Hello, and welcome to Myriora Maths! How do you tell someone exactly where something is on a map or a grid? With coordinates! Let's learn how they work.

A grid has two number lines. The x axis goes across. The y axis goes up. They cross at the origin, the point nought, nought.

A coordinate has two numbers in brackets, like three, two. The first number tells you how far across. The second tells you how far up. So three, two is three across and two up.

The order matters! Two, three is a different point: two across and three up. Remember: along the corridor, then up the stairs.

The axes can carry on past nought, into negative numbers. Then the grid has four parts, called quadrants. The point minus two, three is two to the left, and three up.

Let's try one together. Start at the origin. Go four across and one up. What are the coordinates? Say it out loud!

Across first, then up: four, one!

Here's a question that catches lots of people. Where is the point two, five? Some people go up two and across five. But the first number is always across! Go two across, then five up.

Your turn! A point is three to the left of the origin, and two down. What are its coordinates? Pick the right card. You've got twenty seconds, or pause the video. Go!

Time's up! Left is negative across, and down is negative up. So it's minus three, minus two!

Quick review. Coordinates are two numbers: across first, then up. Along the corridor, then up the stairs. The origin is nought, nought. And negative numbers go left and down. See you next time!