Name
The variable name says what the value represents.
Topic Guide
Variables and State
A variable stores a value that can change. State records which set of rules currently applies.
Why this matters
Scores, timers, fuel, pet moods, and robot modes all have to be remembered. Giving each value a clear name lets a student inspect it while the project runs.
Beyond this topic
A taxi meter keeps the current fare while the vehicle moves. A game score or robot mode also stores information now so that another rule can use it later.
Math and logic
Initial value
The project sets a known value before the test begins.
Update
A particular event changes the value.
State
A label such as PLAYING, CAUGHT, or DELIVERING selects the current rules.
Small examples
Score
Add one when an action finishes, rather than on every frame.
Pet mood
Store a changing need and let it affect the pet's behaviour.
Game state
Use STARTING, PLAYING, WON, and LOST to control separate rules.
Robot mode
Record whether the machine is waiting, moving, or recovering.
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
No reset
A new game inherits the score or mode from the previous run.
Several scripts update one value
The score jumps because more than one rule changes it.
Vague names
Variables called thing or number make the code harder to read.
Hiding the display
Removing a variable monitor from the stage does not erase its value.
Put the idea to work
Scratch & Game Design
Computer Lab Project
The Suspiciously Emotional Space Pet
Create a virtual pet with needs that change over time and actions that affect more than one value.
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
Robotics
Guided Project
micro:bit Reaction Timer
Build a reaction timer with a random delay, an early-press rule, and results in the correct units.
See how it works