A Very Muddy Competition

Students use a third object to compare the lengths of 2 objects indirectly. Note: Activity 2 was updated in the Teacher Edition PDF and in the Teacher Presentation Screens on 1/12/2026.

By Amplify Classroom

Grades: 1st Grade

Subject: Math

Learning goals: Today’s Goals • Use a third object as a tool to compare the lengths of 2 objects indirectly. • Language Goal: Explain a strategy for comparing the lengths of 2 objects that cannot be lined up by their endpoints. (Speaking and Listening) • Language Goal: Justify length comparisons. (Writing) Materials Lesson Resources: Activity 2 PDF; Classroom materials: scissors, string, Words to Describe Length chart (from Lesson 2)