standard_description: Understand subtraction as an unknown-addend problem. For example, subtract 10 – 8 by finding the number that makes 10 when added to 8.
problem_activity: Narrative
The purpose of this warm-up is to elicit the mathematical questions that students produce about shapes composed of pattern blocks, which will be useful when students create and ask questions about shapes in a later activity. While students may notice and wonder many things about the shape, the questions that students can answer about the image are the important discussion points. As students discuss and justify their questions and answers, they share a mathematical claim and the thinking behind it (MP3).
Launch
Groups of 2
Display the image.
“What do you notice? What do you wonder?”
1 minute: quiet think time
Activity
“Discuss your thinking with your partner.”
1 minute: partner discussion
Share and record responses.
Student Facing
Mai used pattern blocks to make this shape.
What do you notice?
What do you wonder?
[IMG]
Student Response
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Activity Synthesis
Reread each of the questions that students shared.
As you read each question, ask: “Can we figure out the answer to this question? How?” (We can figure out how many blue rhombuses she used by counting. We would have to ask Mai why she didn’t use any square pattern blocks.)


aligns: no