standard_description: Determine the unknown whole number in an addition or subtraction equation relating to three whole numbers. For example, determine the unknown number that makes the equation true in each of the equations 8 + ? = 11, 5 = �� – 3, 6 + 6 = ��.
problem_activity: Narrative
The purpose of this activity is for students to choose from activities that offer practice adding two-digit numbers within 100. Students choose from any stage of previously introduced centers.
How Close?
Target Numbers
Five in a Row
Required Materials
Materials to Gather
Materials from previous centers
Required Preparation
Gather materials from:
How Close? Stages 1–3
Target Numbers, Stages 1–3
Five in a Row, Stages 1–6
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 would like to do.”
30 seconds: quiet think time
Activity
Invite students to work at the center of their choice.
10 minutes: center work time
Student Facing
Choose a center.
How Close?
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Target Numbers
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Five in a Row
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Activity Synthesis
“Diego and Elena are playing How Close. Diego has a sum of 91. Elena has a sum of 89. Who gets a point for being closer to 100? How do you know?”


aligns: no