Lesson 11

The purpose of this warm-up is to elicit the idea that expressions and equations can be used to represent different compositions and decompositions of 10, which will be useful when students match compositions and decompositions of 10 to equations in a later activity. While students may notice and wonder many things about these images and expressions, the fact that each image and expression represents a total of 10 is the important discussion point. Students have seen equations in previous lessons, but the synthesis is the first time that students are introduced to the term equation.

• Groups of 2
• Display the image.
• “What do you notice? What do you wonder?”
• 1 minute: quiet think time

• “Discuss your thinking with your partner.”
• 1 minute: partner discussion
• Share and record responses.

• “What is the same about each expression?” (They are all 10.)
• Write \(10 = 7 + 3\).
• “There are 10 counters, 7 red counters and 3 yellow counters. We can write that as 10 is 7 plus 3. When we write \(10 = 7 + 3\), it is called an equation.”
• Repeat the steps with the next 2 images.

• Groups of 2
• “Draw a line from each 10-frame to the equation it matches.”

• 2 minutes: independent work time
• 3 minutes: partner work time

• “What 2 parts do you see on the 10-frame?” 
• “What 2 parts do you see in each equation? Can you find an equation that shows the same parts that you see in the 10-frame?”

• Invite students to share which equation they matched to the first three 10-frames.
• As students share, ask:
  • “How many counters are on this 10-frame?” (10)
  • “What are the 2 parts that you see?” (5 yellow and 5 red)
  • “There are 10 counters, 5 yellow counters and 5 red counters. 10 is 5 plus 5.”
  • Invite students to chorally repeat these equations in unison 1–2 times.

The purpose of this activity is for students to represent equations on fingers. In this activity, students become more comfortable recognizing and representing compositions and decompositions of 10 on their fingers. In future lessons, students may choose to use their fingers to help them find the number that makes 10 when added to a given number. In the activity synthesis, students consider how 2 different drawings can represent the same equation.

• Each student needs at least 2 different colored crayons.

• Groups of 2
• Give each student at least 2 different colored crayons.
• “Color the fingers to show each equation.”

• 3 minutes: independent work time
• “As you continue working, tell your partner about the total and the 2 parts you colored in each set of fingers.”
• 3 minutes: partner work time

• “What are the 2 parts that you see in the equation?” 
• “How can you show the 2 different parts from the equation on the fingers? Which fingers show 1 from the equation? Which fingers show 9?”  

• Write \(10 = 8 + 2\).
• Display a set of hands with 8 fingers colored blue and 2 fingers colored red.
• Display a set of hands with 8 fingers colored red and 2 fingers colored blue.
• “What is the same about how Elena and Tyler colored their hands? What is different about them?” (They both colored 8 and 2. Elena colored 8 blue and 2 red. Tyler colored 8 red and 2 blue.)

The purpose of this activity is for students to choose from activities that offer practice with counting, adding, composing, and decomposing numbers.

Students choose from any stage of previously introduced centers.

• Shake and Spill
• Counting Collections
• Roll and Add

• Gather materials from: 
  • Shake and Spill, Stages 1–3
  • Counting Collections, Stage 1
  • Roll and Add, Stages 1 and 2

• “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. 
• 10 minutes: center work time
• “Choose what you would like to do next.”
• 10 minutes: center work time

• “Which center did you choose today? What did you get better at while working in the center?”