options: Apply properties of operations as strategies to add and subtract. (Students need not use formal terms for these properties.) Examples: If 8 + 3 = 11 is known, then 3 + 8 = 11 is also known. (Commutative property of addition.) To add 2 + 6 + 4, the second two numbers can be added to make a ten, so 2 + 6 + 4 = 2 + 10 = 12. (Associative property of addition.)

Understand subtraction as an unknown-addend problem. For example, subtract 10 – 8 by finding the number that makes 10 when added to 8.
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.
Capture Squares
Shake and Spill
What’s Behind My Back
Required Materials
Materials to Gather
Materials from previous centers
Required Preparation
Gather materials from previous centers:
Capture Squares, Stages 1 and 2
Shake and Spill, Stages 3 and 4
What's Behind My Back, 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.
Capture Squares
[IMG]
Shake and Spill
[IMG]
What's Behind My Back
[IMG]
Activity Synthesis
“Clare was playing What’s Behind My Back with eight connecting cubes. Her partner hid some behind her back and showed her three cubes. Clare counted, ‘7, 6, 5.’ She said her partner was hiding five behind her back. What equation can we write to show how Clare solved the problem?” (
\(8 - 3 = \boxed{5}\)
)


correct_option_index: 1