Lesson 1

This warm-up prompts students to carefully analyze and compare different arrangements of objects. Students notice that the whole group of objects is composed of smaller parts in different ways.

• Groups of 2
• Display 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
• Share and record responses.

• Display the image with four red connecting cubes and two yellow connecting cubes.
• “What are the two groups that you see?” (4 red cubes and 2 yellow cubes)
• Repeat these steps with each image. 

The purpose of this activity is for students to find the total number of pattern blocks in their bag. Students may notice that their pattern blocks are made up of 2 groups, triangles and squares. Each bag of pattern blocks can have a different total number of objects and a different number of triangles and squares. In the synthesis, students share how they found the total number or pattern blocks.

• Each group of 2 needs a bag of up to 10 pattern blocks with a mix of squares and triangles.

• Groups of 2
• Give each group a bag of pattern blocks.
• “Work with your partner to figure out how many pattern blocks you have.”

• 2 minutes: partner work time
• “The sentence says, ‘I have _____ pattern blocks.’ Now write a number on the line to show how many you have.”
• 1 minute: independent work time
• “Pair up with another group. Show them how you figured out how many pattern blocks you have.”
• 4 minutes: small-group work time
• Monitor for a group that counts the 2 groups (3 triangles and 5 squares) as well as all of the pattern blocks (8 pattern blocks). Monitor for another group that only counts all of the pattern blocks. 

If students count each object more than once or do not count some of the objects, consider asking:

• “Can you show me how you counted the pattern blocks? How do you know that you’ve counted all of the pattern blocks?”
• “How could the counting mat (or 5-frame) help you keep track of which pattern blocks you’ve counted?”

• Invite previously identified students to share how they counted their pattern blocks.
• “What is the same and what is different about how each group counted the pattern blocks?” (They both counted all of the blocks. One group counted all of the pattern blocks together and the other group counted the squares first and then the triangles.)
• “When we put together, or add, the number of squares and the number of triangles, we can figure out how many shapes we have altogether.”

The purpose of this activity is for students to find the total number of cubes they have when they add their cubes and their partner’s cubes. In the synthesis students discuss how although someone might count each group separately, that is not enough to determine how many cubes there are altogether. After counting each group, you need to put them together and count all of the cubes to find the total.

• Each student needs a tower with up to 5 connecting cubes.

• Groups of 2
• Give each student a cube tower.
• “You have some cubes and your partner has some cubes. Work together to figure out how many cubes you and your partner have altogether.”

• 2 minutes: partner work time
• Monitor for a group that puts the 2 groups of cubes together and counts all of them to share. Monitor for another group that counts each tower first before putting them together and counting all of the cubes.
• “The sentence says, ‘We have _____ cubes.’ Now write a number to show how many cubes you and your partner have altogether.”
• 30 seconds: independent work time
• Invite previously selected groups to share how they found the total number of cubes.
• “Both groups added the 2 groups of cubes to figure out how many cubes they had altogether.”
• “Now let’s do this one more time. Switch cubes with another group near you. Find out how many cubes you and your partner have now. Write a number to show how many cubes you and your partner have altogether.”
• 2 minutes: partner work time

• Display a tower of 4 cubes and a tower of 3 cubes.
• “This group wants to find how many cubes there are altogether. First they counted and found out there are 4 cubes in this tower and 3 cubes in the other tower. What should they do to figure out how many cubes they have altogether?” (They should put their cubes together and count all of them).
• “How many cubes are there altogether?” (7)
• “One tower had 4 cubes and the other had 3 cubes. We can write that as ’4 and 3.’ When we add the cubes together, we get a total of 7 cubes. 4 and 3 is 7.”

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

Students choose from any stage of previously introduced centers.

• Math Libs
• Match Mine

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

• Gather materials from: 
  • Math Libs
  • Match Mine

• “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

• Display a shape made with 7 pattern blocks, some triangles and some squares.
• “Priya was playing Match Mine and made this shape with her pattern blocks. What do you notice? What do you wonder?”
• If needed, ask “How many pattern blocks did Priya use?”