standard_description: Solve systems of linear equations exactly and approximately (e.g., with graphs), focusing on pairs of linear equations in two variables.
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
Teachers with a valid work email address can
click here to register or sign in
for free access to Student Response.
Activity Synthesis
“Did anyone approach the problem in a different way?”


aligns: no