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Grade 1 Math Units

Unit Plan 15 (Grade 1 Math): Length—Compare & Measure

Compare and order object lengths in Grade 1 by aligning endpoints, then measure with same-size nonstandard units (no gaps/overlaps) to state “__ units long” with clear tool use.

Dr. Michael Kester-Haynes

• 5 min read
Unit Plan 15 (Grade 1 Math): Length—Compare & Measure

Focus: Order and compare object lengths; measure with nonstandard units (cubes, paper clips) and explain how many units long using precise tool use.

Grade Level: 1

Subject Area: Mathematics (Measurement & Data)

Total Unit Duration: 5 sessions (one week), 45–60 minutes per session

I. Introduction

Students build the ideas of longer/shorter/same length by first comparing objects directly (lining up endpoints), then indirectly with a third object, and finally measuring with same-size, non-overlapping units (e.g., paper clips, linking cubes). Emphasis is on tool choice, precision (no gaps, no overlaps), and clear length statements.

Essential Questions

  • How do we know which object is longer or shorter, and why must we align endpoints?
  • Why must measurement units be the same size and placed with no gaps or overlaps?
  • How can a third object help compare two objects indirectly?

II. Objectives and Standards

Learning Objectives — Students will be able to:

  1. Order three or more objects by length and compare two objects indirectly using a third object.
  2. Measure an object using same-size, nonstandard units placed end to end with no gaps/overlaps and report how many units long.
  3. Choose appropriate tools/units and record clear measurement statements with units.
  4. Explain and check reasonableness of comparisons and measurements.

Standards Alignment — CCSS Grade 1 (threaded across the unit)

  • 1.MD.1: Order three objects by length; compare two objects indirectly by using a third object.
  • 1.MD.2: Express the length of an object as a whole number of length units by laying multiple copies of a shorter object (unit) end to end, with no gaps or overlaps.
  • Mathematical Practices: MP.5 (Use appropriate tools strategically) emphasized; MP.2, MP.6 threaded.

Success Criteria — Student Language

  • I can line up endpoints to tell which is longer/shorter.
  • I can say, “This crayon is __ cubes long,” using same-size units with no gaps.
  • I can explain a comparison using models, pictures, or words.