Controlling Variables
📋 What it is
To know what caused a change, keep everything the same except the ONE thing you’re testing.
🗣️ Coach says
A fair test changes only one thing at a time. If you change the water AND the sunlight, you’ll never know which one mattered. Hold everything else steady — that’s a controlled experiment.
🧠 Memory hook
Change ONE thing, keep the rest the SAME. One variable at a time.
😂 Giggle
Why did the pattern-spotter win fast?
Because they read the feedback like a treasure map!
😲 Whoa!
The thing you keep the same is called a "control" — comparing against it is how scientists prove cause, not just coincidence.
✅ Quick check: You give one plant more water AND more sun, and it grows. What can you conclude caused it?
Say your answer out loud first — then reveal.
Nothing for sure — you changed two things, so you can’t tell whether water, sun, or both caused the growth.
Changing more than one variable makes the cause impossible to pin down; isolate one to know.
🧪 Try it! (2 minutes)
Design a fair test for "does warm water dissolve sugar faster?" — list the ONE thing you change and 3 things you keep the same.