The purpose of this activity is for students to solve a Put Together, Total Unknown story problem and a related Put Together/Take Apart, Both Addends Unknown story problem (MP2). Students may use the solution from the first story problem to help them solve the second story problem.

• “How are the two story problems the same?” (They are both about pigeons. There are 10 pigeons in both story problems.)
• “How are the two story problems different?” (In the first problem I know how many pigeons are in the water and how many are on the bench. In the second problem I know that there are 10 pigeons, but I don’t know how many are in the water and how many are on the bench. There is more than 1 way to solve the second story problem.)
• Invite a student who used the solution from the first story problem to solve the second story problem to share.
• “How did you know that there could be 6 pigeons in the water and 4 pigeons on the bench?” (In the first story problem there were 6 in the water and 4 on the bench.)
• “Were there any other ways to solve the second story problem?” (There could be 5 pigeons in the water and 5 on the bench.)
• “In the next activity, we will try to find all of the ways that the 10 pigeons could be in the water and on the bench.”

The purpose of this activity is for students to find all of the compositions and decompositions of 10 in the context of a Put Together/Take Apart, Both Addends Unknown story problem. Monitor for students who:

• Change the number of red and yellow counters on a 10-Frame (MP5).
• Move the beads on a bead tool (MP5).
• Use their knowledge, possibly from memory, of different decompositions of 10.
• Use patterns such as switching the number of pigeons in the water and on the bench (MP7).

The purpose of the Activity Synthesis is to use the 10-Frame and the bead tool to visualize how the parts that make 10 are related, specifically that adding one to one number takes one away from the other number in the decomposition.

• Display a 10-Frame with 9 red counters and 1 yellow counter and a bead tool with 9 beads on the left and 1 bead on the right.

• “How do the 10-Frame and the bead tool show a solution for the story problem?” (There can be 9 pigeons in the water and 1 pigeon on the bench.)
• Switch 1 red counter to yellow, as pictured, and move 1 bead from the right to the left.

• “What if I change 1 red counter to yellow? What if I move 1 bead over?” (Then 8 pigeons are in the water and 2 pigeons are on the bench.)
• “Can I keep changing red counters to yellow? Can I keep moving the beads to the other side? What will happen?” (Yes, more pigeons will be on the bench and fewer pigeons will be in the water.)

The purpose of this activity is for students to choose from activities that offer practice with number and shape concepts. Students choose from five centers introduced in previous units. Students can choose to work at any previously introduced stage of these centers:

• Shake and Spill
• Number Race
• Grab and Count
• What's Behind My Back?
• Pattern Blocks

Students will continue to choose from these centers in upcoming lessons. Keep the materials from each center organized to use each day.

• “What makes working in centers fun for you?“