Sandwich, Salad, or Soup? | CER Class Vote
Virtual Science Teachers
CER Class Challenge

Sandwich, Salad, or Soup?

Make a claim. Use evidence. Explain your reasoning. Then see how the whole class voted.

Three choices only.

1
Vote

Every food must be classified as a sandwich, salad, or soup.

2
Defend

Use specific characteristics as evidence.

3
Reason

Explain why the evidence supports the category.

4
Compare

At the end, study the class graphs and discuss where the evidence was strongest.

Before you begin

How the class vote works

For each food, the teacher records the number of students voting for each category. Do not worry about being “right.” Be ready to explain the rule or criterion behind your choice.

Claim

“I classify this as a sandwich.”

Evidence

“It has bread around a filling.”

Reasoning

“Bread surrounding a filling fits the criterion we are using for a sandwich.”

Challenge

“Would that same criterion work for a taco? If not, we may need to revise it.”

What makes an argument stronger than simply saying, “That’s what I think”?
Choose the best fit. For each food, decide which category it fits into the most: sandwich, salad, or soup. The food does not have to fit perfectly into any of the three categories.
Class data

How did we classify the foods?

Look for consensus, disagreement, and foods where the class had to rely most heavily on definitions and reasoning.

SandwichSaladSoup
From food arguments to science

What did the graphs reveal?

Where did we agree?

Which foods produced a clear class consensus? What evidence made those claims easier to support?

Where did we disagree?

Was the disagreement about the evidence, the definition being used, or how the evidence was interpreted?

Which argument was strongest?

Did it use more evidence, more relevant evidence, clearer reasoning, or a more consistent criterion?

How certain can we be?

What additional evidence or clearer criteria would make a conclusion stronger?

In science, we ask the same kind of question: What conclusion does the evidence support, and how strongly does it support that claim?

Teacher Notes

Purpose

Use a familiar, low-stakes classification problem to introduce CER as a way of making and defending conclusions from evidence. The activity becomes more rigorous as the examples become more ambiguous.

How to run the vote

  • Ask students to choose only Sandwich, Salad, or Soup.
  • Record votes with the + and − buttons or type totals directly.
  • Do not reveal a “correct” answer. Ask students to defend the criterion they used.
  • Move quickly through the first three foods and spend more time on later examples.
  • Votes are saved automatically in this browser until you reset them.

Core prompts

  • What is your claim?
  • What specific evidence supports it?
  • Why does that evidence matter?
  • What criterion are you using?
  • Would that same criterion work for another food?
  • What evidence might someone use to disagree?
  • How strongly does the evidence support your conclusion?

Key debrief idea

Students may look at the same food and use the same observations but reach different conclusions because they are applying different definitions or criteria. Evidence matters, but reasoning explains how the evidence supports the claim.