Which Design Works Better?

SECTION 1

What's Happening? 🔍

🔍 LOOK AT THIS!

The flat raft tips over with just 3 pennies. But the boat with tall sides holds 10 pennies before it sinks! Why did one boat work so much better?

Two paper boats in water — the flat raft tips with 3 pennies while the boat with sides holds 10.

💭 THINKING QUESTIONS

Why do you think the boat with tall sides held more pennies?
How can we use the number of pennies to pick the better boat?

SECTION 2

Big Ideas 💡

When we want to solve a problem, we can try different ideas. We call each idea a design. That means a plan for how to build something.

After we test each design, we get data. Data means the numbers or facts we collect. We use data to decide which design works better!

1

Test Your Designs

You try each design the same way. This is called a fair test. That means you only change one thing at a time.

2

Look at the Data

Count, measure, or observe what happens. The data tells you which design did the job better. The evidence (that means the facts from your test) helps you decide.

✦ KEY TAKEAWAY

KEY TAKEAWAY

SECTION 3

Let's Try It! 🔬

🧪 LET'S TRY THIS!

What you need:

A small ball (like a marble)
Two books (one thin, one thick) to make ramps
A flat board or piece of cardboard
A ruler or tape measure

Steps:

Step 1: Put the board on the thin book. Let the ball roll down. Measure how far it goes on the floor.

Step 2: Put the board on the thick book (taller ramp). Let the ball roll down. Measure how far it goes.

Step 3: Do each test 3 times. Write down all your numbers.

Step 4: Look at your data. Which ramp made the ball go farther?

SECTION 4

What We Found Out 🔎

When we tested both ramps, the tall ramp made the ball roll much farther. The data showed us this! We did not just guess. We measured and compared.

The evidence from our test told us that the tall ramp is the better design. We can explain why too: a taller ramp gives the ball more speed before it hits the floor.

RAMP DESIGN	HOW FAR THE BALL ROLLED
🔵 Design A (Short Ramp)	30 cm
🟢 Design B (Tall Ramp)	60 cm

Look at the table. Design B rolled twice as far! That is strong evidence. When we use data like this, we are thinking like engineers.

✦ KEY TAKEAWAY

KEY TAKEAWAY

SECTION 5

Do You See the Pattern? 🔁

Scientists and engineers always look for patterns. A pattern is when something happens in a similar way again and again.

Here is a big pattern: when we compare two things, data helps us pick the better one. This pattern shows up everywhere!

✦ KEY TAKEAWAY

KEY TAKEAWAY

SECTION 6

People Use This Every Day! 🌍

Real engineers use data to make things better all the time! Here are some examples:

🏠 Building Houses

Engineers test different materials to see which is the strongest. They use data to pick the best wood or bricks for a safe house.

🚗 Making Cars

Car makers test different shapes to see which one moves through the air the easiest. They look at the data and pick the shape that saves the most gas.

You can be an engineer too! Think of a problem you want to solve. Maybe you want to build the tallest tower with blocks. Try two different ways to stack them. Count how many blocks each tower holds. The data will tell you which way is better!

SECTION 7

Words to Know 📖

📖 KEY VOCABULARY

Design — A plan for how to build or make something to solve a problem.
Data — The numbers or facts you collect when you test something.
Evidence — The information from your test that helps you explain what happened.
Fair test — A test where you only change one thing so the comparison is honest.
Compare — To look at two things side by side and see how they are different.

SECTION 8

Show What You Know! ✏️

1

Two teams built bridges out of blocks. They tested how many toy cars each bridge could hold before falling down. Bridge A held 2 toy cars. Bridge B held 5 toy cars. Which bridge worked better at holding cars?

2

Maya tested two paper airplanes. Plane A flew past the red line on the floor. Plane B only flew to the blue line, which was much closer. Maya says Plane B is better because it is prettier. Is Maya using evidence to pick the better design?

3

Two groups built shade structures to keep a sunny spot cooler. After sitting under each one, the class said Structure A felt "a little cooler" and Structure B felt "much cooler" than standing in the sun. Which structure worked better at the job of keeping people cool, and why?

4

Sam's class wanted to keep an ice cube from melting too fast. Group 1 wrapped their ice cube in a cloth. Group 2 wrapped theirs in foil. After 10 minutes, Group 1's ice cube was still big, and Group 2's ice cube was mostly melted. Sam says: "Group 1's design worked better because their ice cube stayed bigger." What makes Sam's answer a good one?

SECTION 9

What's Next? 🔮

🔮 WHAT'S NEXT?