Unit 3, Lesson 18
Make a Yardstick (Optional)
Grade 2
Preparation
Lesson Narrative
This lesson is optional because it does not address any new mathematical content standards. This lesson does provide students with an opportunity to apply precursor skills of mathematical modeling (MP4).
In previous lessons, students made their own centimeter ruler and used different measuring tools such as rulers, measuring tapes, and yardsticks to measure objects.
In this lesson, students make their own yardstick using only a 3-by-5 inch index card as a tool. They use addition and subtraction to make lengths between 1 and 36 inches and mark them on a 3-foot-long strip of chart paper.
When students make their own unit markings, they discover that unequal placement will lead to errors in measurement. The task emphasizes that an inch, or any standard length unit, must be the same size and that there must not be gaps or overlaps between length units. After they create their yardsticks, they compare their yardsticks directly across groups and by measuring the same object. They get a chance to revise their yardsticks based on their observations, an important part of mathematical modeling.
- Representation
- MLR8
- Compare and contrast (orally and in writing) student-created yardsticks and use an understanding of same-size length units to describe differences in measurement results.
- Explain (orally) the strategies used to mark each inch mark to create a yardstick.
- Let’s make a yardstick.
Required Preparation
- Cut the chart paper into strips. Each group of 2 needs a strip of paper that is at least 36 inches long and about 3 inches wide to make their yardstick.
- Students need access to the yardsticks they made in the previous activity.
Teacher Reflection Questions
In what ways did you see students working together and engaging in aspects of mathematical modeling as they created their yardsticks and revised their work?