Lesson 20
More or Less than 10?
Warmup: Estimation Exploration: Close to 10 (10 minutes)
Narrative
Launch
 Groups of 2
 Display the image.
 “What is an estimate that’s too high? Too low? About right?”
 1 minute: quiet think time
Activity
 “Discuss your thinking with your partner.”
 1 minute: partner discussion
 Record responses.
Student Facing
Record an estimate that is:
too low  about right  too high 

Student Response
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Activity Synthesis
 “There are 10 dots. Why was it hard to tell there were 10 dots?” (Usually we see 10 on a 10frame or fingers or with beads. It was hard to see how many there were because they were scattered.)
Activity 1: Use 10 to Estimate (10 minutes)
Narrative
Launch
 Groups of 2
 “Now we are going to look at some pictures of pencils and think about whether there are more than 10 or fewer than 10 pencils without counting them. Write ‘more’ on the line if you think there are more than 10 pencils. Write ‘fewer’ on the line if you think there are fewer than 10 pencils.”
Activity
 3 minutes: independent work time
 Monitor for a student who writes “more” and a student who writes “fewer” for the second problem.
 “Figure out how many pencils are in each picture and write a number on the line. Were your guesses correct?”
 3 minutes: partner work time
Student Facing
Write “more” or “fewer” to finish each sentence.

I think there are ______________________ than 10 pencils.
How many pencils are there? __________

I think there are ______________________ than 10 pencils.
How many pencils are there? __________

I think there are ______________________ than 10 pencils.
How many pencils are there? __________

I think there are ______________________ than 10 pencils.
How many pencils are there? __________

I think there are ______________________ than 10 pencils.
How many pencils are there? __________
Student Response
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Activity Synthesis
 Display the image:
 “Some students said they thought there were more than 10 pencils and some thought there were fewer than 10 pencils. Both of those are good answers.”
 Invite a student to share why they thought there were more than 10.
 Invite a student to share why they thought there were fewer than 10.
 “When groups are close to 10, it is hard to tell whether there are more or fewer than 10 without counting.”
Activity 2: Could She Be Right? (10 minutes)
Narrative
The purpose of this activity is for students to analyze the reasonableness of estimates. It is important for students to know that there is not always a right answer, particularly when the estimate is close to the number of images, as in the third question. It is important that answers to both questions are accepted and the emphasis is on students sharing their reasoning (MP3).
Advances: Speaking, Conversing
Supports accessibility for: SocialEmotional Functioning
Launch
 Groups of 2
 “Elena looked at some pictures and guessed how many there were without counting. We are going to look at the pictures and think about if Elena’s guess could be right.”
Activity
 Read the first problem.
 2 minutes: partner discussion
 Share responses.
 Repeat the steps with the rest of the problems.
Student Facing

Elena says there are about 11 snowflakes.
Do you think she could be right?
Why or why not? 
Elena says there are about 8 flowers.
Do you think she could be right?
Why or why not? 
Elena says there are about 11 suns.
Do you think she could be right?
Why or why not?
Synthesis:
Student Response
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Activity Synthesis
 Display the last image of triangles.
 “Do you think 6 or 14 is a better guess for the number of triangles in this picture? Why?” (14 is a better estimate. I can see a 3 on the top and then there are a lot more, so there are more than 6.)
Activity 3: Centers: Choice Time (25 minutes)
Narrative
The purpose of this activity is for students to choose from activities that offer practice with number and shape concepts. Students choose from 5 centers introduced in previous units. Students can choose to work at any stage of the centers.
 Shake and Spill
 Number Race
 Grab and Count
 What's Behind My Back?
 Pattern Blocks
Students will continue to choose from these centers in upcoming lessons. Keep the materials from each center organized to use each day.
Required Materials
Materials to Gather
Required Preparation
 Gather materials from:
 Shake and Spill
 Number Race
 Grab and Count
 What's Behind My Back?
 Pattern Blocks
Launch
 Groups of 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
Activity
 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
Student Facing
Choose a center.
Shake and Spill
Number Race
Grab and Count
What's Behind My Back?
Pattern Blocks
Activity Synthesis
 “Tell your partner about a time when you used a math tool to help you during centers. How did the tool help you?”
Lesson Synthesis
Lesson Synthesis
“Today we looked at pictures and estimated whether they had more or fewer than 10 things.”
Display a cup with 9 pencils.
“Do you think there are more than 10 or fewer than 10 pencils in the cup? What makes you think that?” (There are about 10 pencils. I see a lot of pencils so there are more than 10 pencils. I think there are fewer than 10 pencils.)
“We can say there are about 10 pencils in the cup.”
Cooldown: Unit 8, Section D Checkpoint (0 minutes)
CoolDown
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