Lesson 68 of 84 · Engineering and Design
Lesson⭐ 30 XP🛠️ Engineer ShopVariables in Experiments (Part 4)
Engineering and Design.
🎯 Your mission
Learn the rule. Then catch nature using it.
⚡ The twist
Constraints make you more creative, not less.
Mind = Blown
🌉 The Eiffel Tower can grow 6 inches taller in summer because metal expands when hot.
Make a hypothesis first
Before you test: how many tries until it works?
What You'll Learn
Variables in experiments include the independent variable (what you change), dependent variable (what you measure), and controlled variables (what you keep the same).
Key Words
- hypothesis
- variable
Steps
Look at the vocabulary words and write a definition for each in your own words.
Build a water filter using a bottle, sand, gravel, cotton, and charcoal. Pour muddy water through and measure how clear the output is.
Watch carefully for any changes and note the time.
Create a data table to organize your measurements.
Check Your Understanding
Question 1
1 of 3What is a hypothesis?
Where you see this in real life
Your phone, your bike, your shoes — all designed with this idea.
Stretch Challenge
Try this in real life this week.
Build something — anything — out of stuff in your recycling bin.
For the dinner table
“What's something around the house you'd redesign — and how?”
Next Smart Experiment
We'll pick an experiment that matches exactly how you're thinking right now.
Share this experiment
Send it to a parent who's looking for a 10-minute kitchen science win.
Checkout complete lesson on Engineering and Design for 4th Grade
Get the full Engineering and Design track as a printable PDF — all lessons, worksheets, and answer keys.