Two number lines
One runs horizontally and the other vertically.
Topic Guide
Coordinates and Movement
Coordinates give every place on the screen an address. Change x to move left or right; change y to move down or up.
Scratch coordinate map
x goes sideways. y goes vertically.
The centre gives every point a shared origin: x: 0, y: 0.
+x / right-x / left+y / up-y / downx: 0, y: 0Ax: 140, y: 90Bx: -150, y: 70Cx: -120, y: -80Dx: 160, y: -95
Why this matters
A coordinate change has a visible result. Students can predict where a sprite will land, define the edge of a map, and read the x and y displays when the movement goes wrong.
Beyond this topic
Maps, screen layouts, robot navigation, drones, and computer vision all represent position with numbers. The dimensions and coordinate systems change, but the need for a shared reference point remains.
Math and logic
Positive and negative
The sign places a point on one side of the origin or the other.
x and y
x controls left and right; y controls down and up.
Change in position
Subtract the starting value from the finishing value to find the change.
The origin
x: 0, y: 0 is the shared reference point at the centre of the stage.
Small examples
Known start
Place a player at x: -180, y: -100 for every test.
Horizontal movement
Change x while keeping y unchanged.
Vertical movement
Change y while keeping x unchanged.
Relative clue
Compare two positions to decide left/right and above/below.
Program connections
Where this topic appears.
Active now
Scratch & Game Design
Students author games, animations, simulations, and strange interactive stories while learning how events, rules, and state fit together.
Active now
Robotics
Students write commands, wire simple circuits, read sensors, and trace physical cause and effect through the Sense–Decide–Act loop.
Coming later
Roblox Studio / Lua
A possible later step from visual programming into Lua, 3D objects, events, and larger game rules.
Coming later
AI & Smart Machines
A possible later program for testing patterns, predictions, prompts, mistakes, and the limits of AI tools.
Common mistakes
Changing the wrong axis
The character moves sideways when it was meant to move vertically.
Using the wrong sign
The sprite heads left when the student predicted right.
Forgetting to reset
The same test gives a different result because the sprite starts somewhere new.
Ignoring the edge
A loop keeps changing position after the sprite reaches the stage boundary.
Mixing up direction and position
Where a sprite faces and where it stands are separate properties.
Adding blocks at random
The useful clues are the sprite's current x and y values.
Put the idea to work
Scratch & Game Design
Guided Project
Escape from the Giant Pigeon
Build a fast chase game with known positions, collision rules, win and loss states, and reliable restart behaviour.
See how it works
Scratch & Game Design
Computer Lab Project
Grandma's Intergalactic Taxi
Navigate a space taxi between coordinate-based pickups and destinations.
See how it works
Scratch & Game Design
Computer Lab Project
Astro-Chicken Rescue
Track several drifting chickens, collect them once each, and stay out of the danger zones.
See how it works