1 of 5

Center Day 2

Grade 2: Unit 3: Lesson 13

Download for free at openupresources.org.

2022 Open Up Resources |

Goals:

Determine the unknown number that makes an equation true.
Estimate and measure objects.

Purpose:

The purpose of this lesson is for students to practice estimating and measuring lengths and adding and subtracting within 100.

Lesson Narrative:

This lesson is optional because it is an opportunity for extra practice that not all classes may need. In Activity 1, students learn a new center, Target Measurements. In this center, students practice estimating and measuring length in inches and centimeters. In Activity 2, students can choose to continue working on Target Measurements, or choose between a previously introduced center and a new stage of the Number Puzzles center, In this stage, called Within 100 with Composing, students work with sums and differences within 100 with composing and decomposing a ten.

2 of 5

Warm-Up: Number Talk-Use Ten to Add

3 of 5

Activity 1:

Introduce Target Measurements, Inches, and Centimeters

Purpose:

The purpose of this activity is for students to learn the first stage of a new center activity, Target Measurements. In this stage, students try to draw a line segment as close as possible to the length of the target measurement in whole inches or centimeters.

Gather:

Rulers
Straightedges

Copy:

Target Measurement Stage 1 Recording Sheet

Launch:

Groups of 2

Give each group a recording sheet and access to centimeter and inch rulers.

“We are going to learn how to play a new center activity called Target Measurements.”

“In this center, you and your partner work together to draw a line that is as close as possible to a target length.”

“When it’s your turn to draw, choose a length in inches or centimeters. If you choose inches, you cannot choose a length longer than 10 inches. If you choose centimeters, you cannot choose a length longer than 30 centimeters.”

Demonstrate choosing a length.

“If you are not drawing, your job is to watch the line and tell your partner to stop when you think the line they are drawing is the same length as the target measurement.”

Select a student volunteer, or ask the class to be your partner. Demonstrate drawing a line segment using a straightedge.

“Then both of you will measure the length of the line and find the difference between the actual length and the target length. The value of the difference is the score for the partner who said ‘stop.’”

Demonstrate measuring the line and recording the target length, actual length, and difference in the place for Partner B on the recording sheet.

“Take turns drawing. After 8 rounds, add up your scores. The partner with the lowest score is the winner.”

Student Work Time:

10 minutes: partner work time
Monitor for students who attempt longer lengths and come close to their target measurement.

Activity Synthesis:

“Did anyone draw a line segment that was the same length as your target length? If not, how close did you get?”

“What was your strategy when working with your partner to draw line segments that were as close as possible to your target length?”

4 of 5

Activity 2: Centers- Introduce Number Puzzles, Within 100 with Composing

Purpose:

The purpose of this activity is for students to learn stage 4 of the Number Puzzles center. Students use digit cards to make addition and subtraction equations true. They work with sums and differences within 100 with composing and decomposing.

After they participate in the center, students can choose to continue to play Number Puzzles or choose one of the estimation and measurement centers.

Estimate and Measure
Target Measurements

Gather:

Materials from previous centers

Copy:

Number Puzzles Addition Stage 4 Gameboard
Number Puzzles Digit Cards

Gather materials from:

Number Puzzles, Stages 4
Estimate and Measure, Stage 2
Target Measurements, Stage 1

Launch:

Groups of 2
Give each group a set of digit cards and a gameboard.
“Now we are going to learn a new way to play the Number Puzzles center.”
“In this stage, you use your digit cards to make each equation true. You may need to think about composing or decomposing a ten.”

Student Work Time:

10 minutes: partner work time
“Now you can choose another center. You can also continue playing Number Puzzles.”
10 minutes: center work time

Activity Synthesis:

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

Lesson Synthesis:

“Today we used digit cards to complete equations with missing numbers. Tell your partner something that helped you figure out how to complete the equation.”

5 of 5

Image Citations

https://pixabay.com/images/id-2724449/

https://pixabay.com/images/id-819587/

https://pixabay.com/images/id-1540436/

https://pixabay.com/images/id-2174052/

https://pixabay.com/images/id-4966995/

https://pixabay.com/images/id-1430103/

https://unsplash.com/photos/PK6NDtsYy00?utm_source=unsplash&utm_medium=referral&utm_content=creditShareLink

Creative Commons BY-NC-SA

Download, adopt, and adapt this Open Educational Resource for your students' needs