standard_description: Recognize angle measure as additive. When an angle is decomposed into non-overlapping parts, the angle measure of the whole is the sum of the angle measures of the parts. Solve addition and subtraction problems to find unknown angles on a diagram in real world and mathematical problems, e.g., by using an equation with a symbol for the unknown angle measure.
problem_activity: Narrative
The purpose of this activity is for students to choose from activities that offer practice adding and subtracting within 10. Students choose from any stage of previously introduced centers.
Number Puzzles
Check it Off
Find the Pair
Required Materials
Materials to Gather
Materials from previous centers
Required Preparation
Gather materials from previous centers:
Number Puzzles, Stage 1
Check It Off, 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 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.
Number Puzzles
[IMG]
Check it Off
[IMG]
Find the Pair
[IMG]
Activity Synthesis
“What method do you use most often to find the value of sums you do not yet know?”


aligns: no