standard_description: Fluently add and subtract within 20 using mental strategies. (See standard 1.OA.6 for a list of mental strategies.) By end of Grade 2, know from memory all sums of two one-digit numbers.
problem_activity: Narrative
The purpose of this activity is for students to choose from activities that focus on counting up to 20 objects or adding and subtracting within 10. Students choose from any stage of previously introduced centers and are encouraged to choose the center that will be most helpful for them at this time.
Counting Collections
Number Race
Check it Off
Five in a Row: Addition and Subtraction
Find the Pair
In the synthesis, students discuss ways they can continue building fluency with addition and subtraction within 10 at home. Consider sending home copies of the center activities for students to play at home.
Required Materials
Materials to Gather
Materials from previous centers
Required Preparation
Gather materials from previous centers:
Counting Collections, Stage 1
Number Race, Stage 3
Check it Off, Stages 1 and 2
Five in a Row: Addition and Subtraction, Stages 1 and 2
Find the Pair, Stage 2
Launch
Groups of 2
“Now you are going to choose from centers we have already learned.”
Display the center choices in the student book.
“Think about what you want to do first.”
30 seconds: quiet think time
Activity
Invite students to work at the center of their choice.
8 minutes: center work time
“Choose what you would like to do next.”
8 minutes: center work time
Student Facing
Choose a center.
Counting Collections
[IMG]
Number Race
[IMG]
Check it Off
[IMG]
Five in a Row: Addition and Subtraction
[IMG]
Find the Pair
[IMG]
Activity Synthesis
“We have been playing a lot of games to help us build fluency with addition and subtraction within 10. How can you continue working on addition and subtraction at home?” (I could use flash cards. I could play these games with my family.)


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