Lesson 12

• Display one expression.
• “Give me a signal when you have an answer and can explain how you got it.”
• 1 minute: quiet think time

• Record answers and strategy.
• Keep expressions and work displayed.
• Repeat with each expression.

• “How can we use the first expression to find the value of the second one?” (I knew that \(17 - 7 = 10\), and then I took away 2 more.)

The purpose of this activity is for students to learn stage 2 of the Sort and Display center. Students sort 20–30 objects into 3 categories and make a picture or bar graph that shows how they sorted. Then, they ask their partner 2 questions that can be answered based on their graph. Students are given an opportunity to sort items, represent how they sorted, and create questions that can be asked about the data in their representation (MP2, MP6).

To connect this center to English Language Arts, students could use books to find a collection. Students look at the cover of a book and choose 3 words or 3 images they think will show up most often in the story and explain why to their partner. Partners record these choices as initial categories. Students then read or look through the book together, explore their prediction and decide together if they want to revise their categories based on what they’ve read. On the second read, they collect and record data for their revised categories. Lastly students create representations based on their data and write 2 “How many?” questions that can be asked about the data in their representations.

• Each group of 2 needs a collection of 20–30 objects that could be sorted into at least 3 categories. Examples: pattern blocks, cubes, sets of books, or a combination of blocks, cubes, and counters.

• Groups of 2
• Give each student a recording sheet.
• “There is a new center called “Sort and Display.”
• Read directions aloud to students.
• “Choose a collection to sort. Sort into 3 categories. Represent the data in a graph that shows how many are in each category.”
• “After you’ve made your representation, you and a partner should ask each other questions about the data in your graph.”

• 12–15 minutes: partner work time
• Monitor for 1–2 graphs to share in the activity synthesis.

• Display student representation.
• “What questions can we ask about the representation of how they sorted?”

The purpose of this activity is for students to choose from activities that focus on adding or subtracting.

Students choose from any stage of previously introduced centers.

• What's Behind My Back?
• How Close?
• Number Puzzles

Gather materials from :

• What's Behind My Back, Stages 2 and 3
• How Close, Stages 1–3
• Number Puzzles, Stages 1 and 2

• “Now you will choose from centers we have already learned that focus on adding and subtracting.”
• 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.
• 15 minutes: center work time

• “Which activity did you choose? What did you like about the activity you chose?”