Lesson 6

The purpose of this Choral Count is to invite students to practice counting by 1 and notice patterns in the count. This will be helpful later in this lesson when students count up to 80 objects.

• “Count by 1, starting at 50.”
• Record as students count.
• Stop counting and recording at 81.

• “What patterns do you see?”
• 1–2 minutes: quiet think time
• Record responses.

• “What do you notice about the numbers as we count?”

The purpose of this activity is for students to organize, count, and represent a collection of 52 objects. Students should have access to double 10-frames, cups, paper plates, or other tools that can help them organize.

Students choose how to count their collection and determine how to represent their count. Some students may count by one as they do not yet trust that counting by ten yields the same result. Other students may apply what they learned in previous lessons and create groups of ten using double-ten frames or other tools (MP5). Some students may continue to count by one after they have organized the cubes into tens while others may count by ten, then one. Regardless of how they count, students need to be careful and organized to make sure they count accurately (MP6).

• Each group of 2 needs 1 bag of 52 single connecting cubes.

• Groups of 2
• Give each group a collection of objects and access to double 10-frames, cups, paper plates, or other tools to help organize their count.
• “You and your partner will get a bag of objects. Your job is to figure out how many are in the bag. Work with your partner to count the collection. Each partner will show on paper how many there are and show how you counted them.”

• 10 minutes: partner work time
• As students work, consider asking:
  • “How did you count? How many are there?”
  • “How can you show this so someone can see exactly how you counted?”
  • “Tell me about what you have written here. How many does it show?”
  • “Does your representation match how you counted?”

• Invite students to share how many objects they counted in the collection.
• “How was this collection different from the collections that you counted before?” (Those collections only had tens and this one has tens and some ones.)
• “Some collections of objects can be organized into groups of ten objects with no leftovers. Some collections of objects have groups of ten and some leftover objects. They have some tens and some ones. We say that this collection has 5 tens and 2 ones.”

The purpose of this activity is for students to analyze a collection of connecting cubes that is arranged in towers of 10. Students analyze another student’s thinking about a representation of 48 cubes in towers of 10. When students explain that they disagree with Noah because a ten must include 10 ones, they show their understanding of a ten and the foundations of the base-ten system (MP3, MP7).

• Groups of 2
• Give students access to connecting cubes in towers of 10 and singles.
• “Noah counted a collection of connecting cubes. He says there are 50 cubes. Do you agree or disagree? Explain how you know. You will have a chance to think about it on your own and talk to your partner about Noah’s thinking before you write your response.”

• 1 minute: quiet think time
• “Share your thinking with your partner.”
• 2 minutes: partner discussion
• “Explain why you agree or disagree with Noah. Write the word ‘agree’ or ‘disagree’ in the first blank. Then write why you agree or disagree.”
• 3 minutes: independent work time

If students attempt to check Noah's count by counting all the cubes by one, consider asking:

• “How are you checking to see if there are 50 cubes?”
• “How could you use what you know about groups of ten to check Noah’s thinking?”

• Invite students to share whether they agree or disagree, and their reasons.
• If needed, ask “How do you know there are not 50 cubes?” (50 is 5 tens. There are only 4 tens here. The last tower isn’t 10. There are 4 tens and 8 ones.)

The purpose of this activity is for students to choose from activities that offer practice adding and subtracting. Students choose from any stage of previously introduced centers.

• Check It Off
• Five in a Row
• Number Puzzles

• Gather materials from previous centers: 
  • Check It Off, Stages 1–3
  • Five in a Row, Stages 1–4
  • Number Puzzles, Stages 1 and 2

• Groups of 2
• “Now you 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.”
• 30 seconds: quiet think time

• Invite students to work at the center of their choice. 
• 10 minutes: center work time

• “Jada is playing Check It Off. She still needs to check off 30. What numbers could Jada pick to get a sum or difference of 30?” (20 and 10, 90 and 60, 80 and 50, 70 and 40, 60 and 30, 50 and 20, 40 and 10)