standard_description: Understand the meaning of the equal sign, and determine if equations involving addition and subtraction are true or false. For example, which of the following equations are true and which are false? 6 = 6, 7 = 8 – 1, 5 + 2 = 2 + 5, 4 + 1 = 5 + 2.
problem_activity: Narrative
The purpose of this Number Talk is to elicit understandings students have for adding and subtracting within 20 using the strategy of making a ten.
Launch
Display one expression.
“Give me a signal when you have an answer and can explain how you got it.”
1 minute: quiet think time
Activity
Record answers and strategy.
Keep expressions and work displayed.
Repeat with each expression.
Student Facing
Find the value of each expression mentally.
\(10 + 4\)
\(9 + 4\)
\(9 + 6\)
\(15 – 6\)
Student Response
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Activity Synthesis
“Did anyone approach the problem in a different way?”


aligns: no