7th Grade CER History Detective - Lewis & Clark Expeditions
In history, we don’t just memorize facts — we explain how and why events happened. That means using Claim–Evidence–Reasoning (CER):
- Claim: Your answer to the question.
- Evidence: Facts or details that support your claim.
- Reasoning: The thinking that connects the evidence to your claim.
Today, you’ll review CER with a simple example, then practice identifying and writing each part. Finally, you’ll answer a real historical question from our time period — just like you might see on a LEAP Extended Response.
Group 1
Below are pieces of evidence from a weather event. Match each piece of evidence to the reasoning that best explains it.
Source 1.1
"Prompt: What weather event do you think happened last night?"
Claim: A statement that answers a question.
Example: It rained last night.
Evidence: Facts or clues that support your claim.
- The ground is wet
- the puddles are full
- leaves are sticking to the sidewalk
Reasoning: Explain how the evidence proves your claim.
- Rain would make the ground wet and cause puddles to form.
- It can also make leaves stick to the ground because of the water.
- These clues all point to rainfall as the cause.
Full Answer:
I think it rained last night. When I look outside the ground is wet, the puddles are full, and leaves are sticking to the sidewalk. Rain would make the ground wet causing puddles to form. It can also make the leaves stick to the ground because of the water.
Question 1a
Evidence: The streets are wet.
Which reasoning fits this evidence best?
Question 1b
Evidence: The puddles are full.
Which reasoning fits this evidence best?
Question 1c
Evidence: Leaves are sticking to the road.
Which reasoning fits this evidence best?
Group 2
Choose the best definition for each CER term.
Question 2a
What is a Claim in CER?
Question 2b
What is Evidence in CER?
Question 2c
What is Reasoning in CER?
Group 3
Scenario: You discover a leather satchel filled with: a journal filled with maps and plant sketches, a compass, a rifle, a folding telescope, glass sample jars, and a small American flag on a stick.
Question 3a
Where or why is this person most likely traveling?
Group 4
Refer to the items in the satchel from the previous question.
Question 4a
Which 2–3 of the satchel’s items best support your claim?
Group 5
Refer to the items you chose as evidence in the previous question.
Question 5a
Explain how the items you chose support your claim.
Question 5b
Write a CER paragraph about where the person was going and why you think that.
Source 5b.1
Now, combine your Claim, Evidence, and Reasoning from the mystery backpack into one paragraph. Use sentence starters like:
- I think...
- because...
- For example...
- This shows that...
Group 6
Read the passage below about the Lewis and Clark Expedition. Use it to help answer the next question.
Source 6.1
In 1803, President Thomas Jefferson sent Meriwether Lewis and William Clark to explore the newly acquired Louisiana Territory. Their mission, known as the Lewis and Clark Expedition, had several goals. First, they were to map the land and find a water route to the Pacific Ocean. They also needed to document the plants, animals, and geography they found, and to establish friendly relationships with Native American nations along the way. Lewis and Clark’s team, called the Corps of Discovery, traveled up the Missouri River, across the Great Plains, and over the Rocky Mountains. The journey was difficult, with harsh weather, dangerous terrain, and limited supplies. Along the way, they met many Native American nations, who sometimes helped them with food, guidance, and information about the land. The expedition provided valuable maps and information about the West. It encouraged more Americans to move west, increased knowledge about natural resources, and helped the United States claim more land. The Lewis and Clark Expedition played a key role in the growth and development of the United States by opening up the West for settlement and showing the possibilities of the new territory.
Adapted from National Park Service and Library of Congress resources.
Group 7
Using what you know about history and evidence from the text, explain how the Lewis and Clark expedition impacted the growth and development of the United States. Make a claim, support it with at least two pieces of evidence from the text, and explain how your evidence supports your claim.
Question 7a
Using what you know about history and evidence from the text, explain how the Lewis and Clark expedition impacted the growth and development of the United States. Make a claim, support it with at least two pieces of evidence from the text, and explain how your evidence supports your claim.
Group 8
Think about how you answer questions in history using CER.
Question 8a
How does using CER change the way you answer questions in history? Does it make your answers stronger? Why or why not?
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