Where Does the Puddle Go?
Prove that water goes somewhere when it disappears.
1 week🔬 Science🔢 Math✏️ Writing
What you need
- three identical cups
- water
- a marker
- cling film if you have it
Nothing to buy and nothing to print — if you do not have one of these, swap it for whatever you do have.
The steps
Day 1
Three cups
Fill three cups to the same line. Cover one with cling film. Put one in the sun and one in the shade.
📷 Take a photo
Day 2
Predict
Write which cup will lose most water, and why, BEFORE you look.
✍️ Write a few sentences
Say this: “Write the prediction down. It only counts if you cannot change it later.”
Day 3
Mark the levels
Mark each cup's level with a line and the date.
📷 Take a photo
Day 4
Measure
Measure how far each level has dropped, in millimetres.
🔢 Write the number down
Day 5
Explain
Which lost most? Was your prediction right? Where did the water actually go?
✍️ Write a few sentences
How to score it
You score this, not us. Pick the description that actually matches what they did.
Fair test
- 1. Cups differed
- 2. Same cups, different fill
- 3. Same cups, same fill
- 4. Same cups, same fill, one variable changed
Prediction
- 1. No prediction
- 2. Predicted
- 3. Predicted with a reason
- 4. Predicted with a reason and compared it honestly to the result
Explanation
- 1. Water vanished
- 2. Water dried up
- 3. Water evaporated
- 4. Water evaporated, and the covered cup shows where it would have gone
What goes in the portfolio
A table of water levels over five days and a written explanation of the difference.