The purpose of this activity is for students to decompose 6 into 2 parts. Students see that the total number of cubes remains the same when it is decomposed into 2 parts. Although students may notice that they decompose 6 in different ways, that idea isn't the focus until the next activity.

• Invite a student to share.
• “How many cubes did you have in your hand? How many cubes were on your desk?”
• Write an expression to represent the parts.
• “How many cubes did you have in all?” (6)
• “The total number of cubes stays the same when we break them up into 2 parts.”

The purpose of this activity is for students to see that numbers can be decomposed in different ways. Students analyze two different ways that 4 cubes are decomposed into two groups. They determine that although they are decomposed into different-sized parts, they both represent a total of 4.

• “Do Diego and Lin both have 4 cubes?”
• Invite previously identified students to share.
• “What parts did Diego break 4 into? (3 and 1)
• Write .
• “What parts did Lin break 4 into?” (2 and 2)
• Write .
• “Diego and Lin showed us that we can break numbers apart in different ways.”

The purpose of this activity is for students to learn Stage 1 of the Check it Off center. Before beginning, remove cards showing the numbers 6–10 and set aside. Students take turns picking two number cards (0–5) and find the value of their sum. Students check off the number that represents the value of the sum (0–10) and then fill in the addition expression on the recording sheet. The partner who checks off the most numbers wins.

After they participate in the center, students choose any previously introduced stage from these centers:

• Find the Value of Expressions
• Bingo
• Shake and Spill

Students will choose from these centers throughout the section. Keep materials from these centers organized to use each day.

• “Choose 1 expression that you wrote on your recording sheet. Tell your partner how you can find the value of that expression.”