standard_description: Add and subtract within 20, demonstrating fluency for addition and subtraction within 10. Use strategies such as counting on; making ten (e.g., 8 + 6 = 8 + 2 + 4 = 10 + 4 = 14); decomposing a number leading to a ten (e.g., 13 – 4 = 13 – 3 – 1 = 10 – 1 = 9); using the relationship between addition and subtraction (e.g., knowing that 8 + 4 = 12, one knows 12 – 8 = 4); and creating equivalent but easier or known sums (e.g., adding 6 + 7 by creating the known equivalent 6 + 6 + 1 = 12 + 1 = 13).
problem_activity: Narrative
The purpose of this activity is for students to use what they know about making a ten to identify which addition expressions are equivalent to
\(10 + n\)
expressions. Students should have access to double 10-frames and connecting cubes or two-color counters.
The Compare Stage 2 Addition Cards will be used again in a later lesson.
Required Materials
Materials to Gather
Connecting cubes or two-color counters
Double 10-frames
Materials to Copy
Compare Stage 2 Addition Cards to 20
Required Preparation
Create a set of Compare Stage 2 Addition Cards to 20 from the blackline master for each group of 3.
Launch
Groups of 3
Give each group a set of cards and access to double 10-frames and connecting cubes or two-color counters.
Activity
Read the task statement.
8 minutes: small-group work
Student Facing
Take out all the expression cards that have the number 10.
Mix up the rest of the cards.
Pick a card.
Place the card under the expression with 10 that it is equal to.
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Student Response
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Activity Synthesis
“We are going to create a poster and do a Gallery Walk.”


aligns: yes