🔬 Think Like a Scientist! Using the C.E.R. Strategy

7th Grade Science | Scientific Thinking and Investigation

Have you ever had to explain why you believe something is true? Maybe you had to prove your answer to a teacher or explain your side of an argument to a friend.

Scientists do this all the time!

In science, it is not enough to say what you think. You must be able to support your ideas with evidence and explain your thinking.

One way scientists do this is by using the C.E.R. Strategy.

🧠 What Is C.E.R.?

C.E.R. stands for Claim, Evidence, and Reasoning.

This strategy helps us organize our thoughts and build strong scientific arguments.

C = CLAIM: What do you think?

A claim is a statement that answers a scientific question.

Your claim should be clear and easy to understand. It tells the reader what you believe based on what you have learned or observed.

Example:

Question: Do plants need sunlight to grow?

Claim: Plants need sunlight to grow and stay healthy.

A claim tells us your answer, but it does not explain how you know it is true. That is where evidence comes in!

E = EVIDENCE: How do you know?

Evidence is the information that supports your claim.

Scientists collect evidence by making observations, completing experiments, taking measurements, and studying information.

Good evidence includes facts, not just opinions.

Example:

Plants placed near a sunny window grew taller than plants kept in a dark room.

This evidence helps support our claim about sunlight.

Remember: Evidence is what you observe or measure, not what you guess!

R = REASONING: Why does your evidence matter?

Reasoning explains how your evidence supports your claim.

This is where you connect what you observed to what you know about science.

Example:

Plants use sunlight to make food through a process called photosynthesis. Without enough light, most plants cannot make the food they need to grow.

Reasoning helps your reader understand WHY your evidence supports your claim.

🔥 Let’s Investigate: Is Fire Alive?

Imagine sitting around a campfire.

You notice that the flames move, the fire grows larger when more wood is added, and the fire gives off heat.

Some of these actions may remind you of living things!

But does that mean fire is alive?

Think about these questions:

Can something grow without being alive?
Does movement always mean something is living?
How can we tell the difference between living and nonliving things?
What evidence would help us answer these questions?

In our first investigation, you will observe a campfire and compare what you see to the characteristics of living things.

Your job is not to make a quick guess. Your job is to think like a scientist!

You will collect observations, study what makes something alive, and use the C.E.R. Strategy to explain your answer.

✏️ Sentence Starters to Help You

Sometimes getting started is the hardest part! Use these sentence starters when writing your scientific argument.

CLAIM

I believe that…
My claim is…
Based on my observations…

EVIDENCE

I observed that…
The investigation showed…
One piece of evidence is…

REASONING

This evidence supports my claim because…
I know this because…
This connects to what we learned about…

🌟 Why Does C.E.R. Matter?

We will use C.E.R. throughout the school year.

It will help you explain your answers, write about experiments, understand scientific ideas, and support your thinking with facts.

You do not have to be a perfect writer to make a strong scientific argument.

You just need to remember three things:

CLAIM: Tell us what you think.

EVIDENCE: Show us how you know.

REASONING: Explain why your evidence supports your answer.

The more you practice, the stronger your scientific thinking will become!

🎯 Your Science Challenge!

Before beginning our campfire investigation, think about this question:

Can something act like a living thing without actually being alive?

Write down two things you already know about living things and one question you have about fire.

Keep your ideas ready! You will use them as you begin your investigation.

Remember: Great scientists do not just give answers. They use evidence to explain them! 🔬

Next Steps:

Group Work: Work in groups of 2-3 to complete the Encounter the Phenomenon activity on pages 7-9 of your workbook.
On Your Own: Watch the video below and then complete the Investigation Activity on page 10. What Makes Something Alive? video.
Turn It In: Put a post-it note on page 10 of your workbook. Turn your workbook in by placing it neatly in the black crate.
When you are done: Review the What to do When You Are Finished post.