Lesson 4

• “Let’s count to 60.”
• Count to 60.

• “Now, start at the number 9 and count to 20.”
• Count on from 9 to 20.
• Repeat 3–4 times starting with other numbers within 10.

• “How did you know what number to say after 9?”
• “We can start counting at numbers other than 1. When we count on, we think about what number comes next when we count.”

The purpose of this activity is to look for patterns in decompositions. The decompositions in the activity are presented in a way to encourage students to look for patterns, such as one addend getting larger while the other gets smaller, and use this information to determine if there are other possible decompositions. When students look for patterns, they look for and make use of structure (MP7). When they write expressions to represent diagrams they reason abstractly and quantitatively (MP2).

• Groups of 2
• Give students access to connecting cubes.
• “Andre and Priya snapped a tower with 8 cubes. They used 2 different colors to show how they broke their tower each time. Write an expression to represent the 2 parts that they snapped each tower into.”
• 2 minutes: partner work time
• “Look at the cubes and the expressions. What patterns do you notice?” (There are more yellow each time. There is 1 more yellow and 1 fewer blue each time. The first number in the expression is getting bigger)

• 3 minutes: partner discussion

• “Did Andre and Priya find all of the ways to break apart the tower of 8 cubes? What makes you think that?” (They could have broken the tower into 6 yellow and 2 blue.)

The purpose of this activity is for students to find all the different decompositions of 7.

• Groups of 2
• Give groups access to connecting cubes and two-color counters.
• “Find all the different ways you can break apart 7 into 2 parts. Show your thinking using objects, drawings, numbers, or words. ”

• 5 minutes: partner work time
• “If you haven’t already, write an expression to show each way that you broke apart 7.”
• 2 minutes: partner work time

• Invite 2–3 groups to share.
• “How do you know you found all the ways to break apart 7?”
• “Did anyone find another way to break apart 7?” 

The purpose of this activity is for students to choose from activities that offer practice with addition and subtraction.

Students choose from any stage of previously introduced centers.

• What’s Behind My Back?
• Check It Off
• Find the Value of Expressions
• Bingo
• Shake and Spill

• Gather materials from: 
  • What’s Behind My Back?, Stage 1
  • Check It Off, Stage 1
  • Find the Value of Expressions, Stage 1
  • Bingo, Stages 1–3
  • Shake and Spill, Stages 1–3

• “Today we 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 first.”
• 30 seconds: quiet think time

• Invite students to work at the center of their choice. 
• 8 minutes: center work time
• “Choose what you would like to do next.”
• 8 minutes: center work time

• “What is one thing from your work in centers today that you would like to continue to get better at?”