Lesson 11

The purpose of this warm-up is for students to extend the verbal count sequence to 90 and to count on from a given number. As students count, point to the numbers posted so that students can follow along.

• “Let’s count to 90.”
• Count to 90 1–2 times as a class.

• “Now, start at the number 13 and count to 20.”
• Count on from 13 to 20.
• Record as students count.
• Repeat 3–4 times starting with other numbers within 20.

• “Take turns counting on with your partner. Tell your partner which number to start counting at and which number to stop counting at.”

The purpose of this activity is for students to use the 10 ones and some more ones structure of numbers 11–19 to help accurately count images in organized arrangements (MP6, MP7). Some methods that students may use to count the shapes include:

• Begin at 1 to count each shape, even after they have circled 10 shapes.
• Circle 10 shapes and know that 10 shapes and 2 shapes is 12 shapes without counting based on experiences in previous lessons.
• Circle 10 shapes and count on from 10 to determine the total number of shapes.

• Groups of 2
• Display the images.
• “What do you notice? What do you wonder?” (I notice that there are a lot of triangles in the line. I notice that the triangles are circled in the second picture. I notice that there are 10 triangles and 4 triangles. There are 14 triangles. I wonder why one of them has 10 triangles circled. I wonder if there are 14 triangles in the first picture.)
• 30 seconds: quiet think time
• 1 minute: partner discussion
• Share and record responses.
• “Circle a group of 10 squares in the first problem.”
• 30 seconds: independent work time
• “Share with your partner. Did you both circle the same 10 squares?”
• 30 seconds: partner discussion
• “How many squares are there? How do you know?” (13. There are 10 and 3 more.)
• 1 minute: quiet think time
• Share responses.
• “Figure out how many shapes there are. You may circle a group of 10 if it can help you figure out how many there are. Write a number to show how many shapes there are.”

• 5 minutes: independent work time
• Monitor for students who use the methods described in the activity narrative to determine how many shapes there are altogether.

If students count the 10 shapes that they have circled each time, consider asking:

• “How many shapes did you circle? How do you know?”
• If students answer 10 without counting, ask, “Can you figure out how many shapes there are without counting the shapes that you circled again?” 

• Invite a student who circled 10 shapes and just knew that 10 shapes and _____ shapes is _____ to share.
• “How did circling 10 of the shapes help you figure out how many shapes there were altogether?” (I circled 10 shapes and saw that there were 3 more shapes. I know that 10 and 3 is 13.)
• “10 shapes and 3 shapes is 13 shapes.”
• Invite a student who circled 10 shapes and counted on to determine the total number of shapes to share.
• “How did circling 10 of the shapes help you figure out how many shapes there were altogether?” (I circled 10 shapes. I knew that there were 10 shapes in my circle, so then I counted 11, 12, 13. I didn't have to count the 10 shapes again.)
• As each student shares, record the number of shapes with an equation, such as \(10 + 3 = 13\).

The purpose of this activity is for students to show the 10 ones and some more ones structure of numbers 11–19 as they color images to match expressions. Once students color in the expressions, they figure out the total number of shapes and fill in an equation. Because students are coloring in the shapes to show \(10 + \underline{\hspace{1 cm}}\), students may count on from 10 to determine the total number of shapes. It is important that students connect their equations to the corresponding representations (MP2). While counting on from 10 is highlighted in the activity synthesis, counting on to determine the total is not an expectation in kindergarten.

• Students need access to at least 2 different colored crayons, colored pencils, or markers.

• Groups of 2
• Give each student access to at least two different colored crayons.
• “Color the shapes to show each expression. Then complete the equation to show how many shapes there are altogether.”

• 2 minutes: independent work time
• 3 minutes: partner work time
• Monitor for students who count on from 10.

• Invite a student who counted all of the shapes to share.
• Invite a student who counted on from 10 to share.
• “What is the same and what is different about how _____ and _____ counted the shapes?” (They both counted all shapes. _____ started counting at 1. _____ didn’t count the shapes that they colored because they knew that there were 10.)

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

Students choose from any stage of previously introduced centers.

• Find the Value of Expressions
• Make or Break Apart Numbers
• Bingo

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

• Gather materials from:
  • Find the Value of Expressions, Stage 1
  • Make or Break Apart Numbers, Stages 1 and 2
  • Bingo, Stages 1-4

• “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

• “What did you like about the activities you worked on today?”