Lesson 2

This warm-up prompts students to compare four designs of pattern blocks. It draws students’ attention to the total number of pattern blocks in a design and the numbers of shapes within each group in the design, which will be useful when students create and compare pattern block designs in upcoming activities. This activity gives students a reason to attend to the features of each representation and to use language precisely (MP6).

• Groups of 2
• Display the image.
• “Pick one that doesn’t belong. Be ready to share why it doesn’t belong.”
• 1 minute: quiet think time

• “Discuss your thinking with your partner.”
• 2–3 minutes: partner discussion
• Record responses.

• “Let’s find at least one reason why each one doesn’t belong.”

The purpose of this activity is for students to compose a group of 7 objects and identify the parts and total in the design. In the activity synthesis, students share their designs and discuss that while the total number of pattern blocks stays the same, the numbers of each type of pattern block changes. As students share, the teacher records an expression to represent the parts in each design.

• Groups of 2
• Give students pattern blocks and crayons. 
• “Create a design with 7 pattern blocks. Use only green triangles and orange squares. Draw a picture of your design and write numbers to show how many green triangles and how many orange squares you used.”

• 3 minutes: independent work time
• Monitor for students who use different numbers of triangles and squares to create a design with 7 pattern blocks. 
• “Share your design with your partner. Tell them how many green triangles you used, how many orange squares you used, and how many pattern blocks you used altogether.” 
• 2 minutes: partner discussion

• Invite 2–3 students who used different numbers of squares and triangles to share their designs.
• “What parts do you see in _____’s design?” (There is a group of 5 green triangles. There is a group of 2 orange squares.)
• As students share, record each design with an expression. For example:
• “In the past, we used expressions to show when something was added or taken away. We can also write an expression to show the parts that we see. This design has 7 pattern blocks, 5 green triangles and 2 orange squares. I can write that as \(5 + 2\).”
• “What is the same about each design? What is different?” (They each have 7 pattern blocks. They each have only squares and triangles. The designs look different. They used different numbers of squares and triangles.)
• If needed, say “Each design had 7 pattern blocks, but they used different numbers of green triangles and orange squares. There were still 7 pattern blocks.”

The purpose of this activity is for students to see 8 pattern blocks broken into 2 parts in multiple ways. Students represent each pattern block design with an expression. When students write an expression to represent the pattern blocks they reason abstractly and quantitatively (MP2).

• Groups of 2
• Give students pattern blocks.
• “Make another design with 7 pattern blocks, using only green triangles and orange squares. Use a different number of orange squares and green triangles than you did in the previous activity.”
• 2 minutes: independent work time
• “Share your design with your partner. Tell your partner how many pattern blocks you used altogether, and how many green triangles and orange squares you used.” 
• 2 minutes: partner discussion.
• “Here are some pattern block designs that Han made with 8 pattern blocks. Write an expression to show how many green triangles and red trapezoids he used in each design.”

• 3 minutes: partner work time

• “What are the different ways to make 8 that you found in the designs?” (5 and 3, 4 and 4, 6 and 2)
• Display the first and third designs.
• “What is the same about these designs? What is different?” (They both show 5 and 3. They both have 8 pattern blocks. One used more red trapezoids and one used more green triangles.)

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.

• Check It Off
• Find the Value of Expressions
• Bingo
• Shake and Spill

• Gather materials from: 
  • 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

• Display 4 red counters and 2 yellow counters.
• “Andre was playing Shake and Spill and this is what his counters looked like. What are the two parts that you see in the counters?” (4 and 2)
• “If Andre shakes and spills 6 counters again, what is a different way that his counters could look?” (3 red and 3 yellow, 5 red and 1 yellow)