Grade: Grade 1 Subject: Science Unit: Habitats Lesson: 5 of 6 ACT: Science

CER Writing: Explaining Animal Habitats

Learn

Scientists don't just discover things - they also explain what they learned! When scientists write about their discoveries, they use something called CER.

What is CER?

CER stands for three important parts of science writing:

  • C = Claim - What do you think? (Your answer or idea)
  • E = Evidence - How do you know? (Facts and observations that support your claim)
  • R = Reasoning - Why does it matter? (Explain how your evidence supports your claim)

Why Do Scientists Use CER?

  • CER helps scientists explain their thinking clearly
  • CER shows that scientists have proof for their ideas
  • CER helps other people understand and learn

Simple Way to Remember CER

LetterMeansQuestion to Ask
CClaim"What do I think?"
EEvidence"What did I see or learn?"
RReasoning"Why does my evidence prove my claim?"

Sentence Starters for CER

Claim starters:

  • "I think that..."
  • "I believe..."
  • "The answer is..."

Evidence starters:

  • "I know this because..."
  • "I observed that..."
  • "The data shows..."

Reasoning starters:

  • "This proves my claim because..."
  • "This is important because..."
  • "This means that..."

Examples

Example 1: Forest Habitat CER

Question: Can a squirrel live in a forest habitat?

Claim: I think a squirrel CAN live in a forest habitat.

Evidence: I observed that forests have trees with acorns for food. Forests have streams for water. Squirrels can build nests in tree branches for shelter.

Reasoning: This proves my claim because squirrels can find all four things they need (food, water, shelter, and space) in a forest.

Example 2: Ocean Habitat CER

Question: Can a fish live in a desert habitat?

Claim: I think a fish CANNOT live in a desert habitat.

Evidence: Fish need water to breathe and swim. Deserts have very little water. Fish would not have shelter in sand.

Reasoning: This proves my claim because fish cannot get the water they need in a desert. Without water, fish cannot survive.

Example 3: Comparing Habitats CER

Question: Do more animals live in a forest or a desert?

Claim: I believe more animals live in a forest than a desert.

Evidence: My data shows that scientists counted 45 animals in a forest and only 12 animals in a desert. The forest had more food, water, and shelter available.

Reasoning: This proves my claim because forests provide more of what animals need to survive. When there is more food and water, more animals can live there.

Practice

Practice using CER to write about animal habitats!

1. What does the "C" in CER stand for?

A) Cat   B) Claim   C) Count   D) Color

2. What does the "E" in CER stand for?

A) Elephant   B) Easy   C) Evidence   D) End

3. What does the "R" in CER stand for?

A) Rabbit   B) Run   C) Read   D) Reasoning

4. Which sentence is a CLAIM?

A) "I saw a bird eating seeds."   B) "I think birds live in trees."   C) "Birds have feathers."   D) "The bird flew away."

5. Which sentence is EVIDENCE?

A) "I think polar bears are white."   B) "Polar bears are cool."   C) "I observed that polar bears eat fish and seals."   D) "I like polar bears."

6. A student wrote: "Fish live in water." Is this a claim, evidence, or reasoning?

A) Claim   B) Evidence   C) Reasoning   D) None of these

7. Write a CLAIM to answer this question: "Can a frog live in a pond?"

Start with "I think..." or "I believe..."

8. Write EVIDENCE for your claim in question 7. What do you know about frogs and ponds?

Start with "I know this because..." or "I observed that..."

9. Write REASONING for your claim. Why does your evidence prove your claim?

Start with "This proves my claim because..."

10. Write a complete CER paragraph to answer: "Is a forest a good habitat for a deer?"

Use all three parts:

  • C (Claim): _____
  • E (Evidence): _____
  • R (Reasoning): _____

11. What is WRONG with this CER?

Claim: I think dogs are the best pets.

Evidence: My dog is fluffy.

Reasoning: Dogs are fun.

A) The claim is wrong   B) The evidence doesn't prove the claim   C) There is no claim   D) Nothing is wrong

12. Why do scientists use CER when they write?

A) To make writing longer   B) To explain their thinking with proof   C) To confuse people   D) Because they have to

Check Your Understanding

Question 1: Put these CER parts in the correct order: Evidence, Reasoning, Claim

Show Answer

The correct order is: Claim, Evidence, Reasoning (C-E-R). First you state what you think, then you show your proof, then you explain why your proof supports your claim.

Question 2: What makes good evidence?

Show Answer

Good evidence includes facts, observations, data, or things you learned that support your claim. It should be something you saw, counted, or read about - not just an opinion!

Question 3: How is CER like being a detective?

Show Answer

Just like a detective, you make a claim (what you think happened), find evidence (clues that prove it), and explain your reasoning (why the clues prove you are right). Scientists are like detectives who solve mysteries about nature!

Next Steps

  • Practice using CER when you explain your thinking in science AND other subjects
  • Look for claims, evidence, and reasoning when reading books
  • Continue to the Unit Checkpoint to review everything you learned about habitats