Unit 6, Lesson 2
Compare the Lengths of Objects Indirectly
Grade 1
Preparation
Lesson Narrative
In the previous lesson, students ordered three objects by length by lining them up at their endpoints. Students used complete sentences to describe the relative lengths of objects.
The purpose of this lesson is for students to compare the lengths of two objects indirectly by comparing them with the length of a third object. Indirect comparison allows students to compare the lengths of objects that are difficult to compare by lining them up. The ideas in this lesson lead to the understanding that iterated length units can be used to measure and compare the lengths of objects. Students may intuitively understand the concept of indirect comparison, and this lesson provides an opportunity for those students to develop language to communicate that understanding (MP6).
- Action and Expression
- MLR8
- Use “longer than” and “shorter than” (orally and in writing) to compare objects that are shorter and longer than the length of a given object.
- Let’s compare 2 objects using a third object.
Required Preparation
- Each group of 4 students needs access to the materials from the previous lesson and 1 unsharpened pencil.
- Create a two-column chart with the headings “longer” and “shorter” for the Synthesis.
- Each group of 2 needs a piece of string longer than the length of the side of a desk or table in the classroom.
Suggested Centers
NoneTeacher Reflection Questions
How did students explain how they used a tool (like the pencil or the string) to compare lengths indirectly? What did their explanations show they understand about comparing attributes like length?