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Grade 1 Math Units

Unit Plan 26 (Grade 1 Math): Length & Units—Measure to Compare

Measure with same-sized nonstandard units (no gaps/overlaps), compare lengths, and show “how much longer” on a number line with clear, accurate recording.

Dr. Michael Kester-Haynes

• 5 min read
Unit Plan 26 (Grade 1 Math): Length & Units—Measure to Compare

Focus: Measure objects using same-sized, nonstandard units (e.g., cubes, paperclips), avoid gaps/overlaps, and compare lengths; represent lengths on a number line to reason about difference.

Grade Level: 1

Subject Area: Mathematics (Measurement & Data)

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

I. Introduction

Students learn what a unit is and why using same-sized units matters. They practice iterating a unit with no gaps or overlaps, align to zero/endpoint, and record lengths. Then they compare “longer/shorter” and “how much longer,” using a number line to model differences.

Essential Questions

  • What is a unit of length, and why must units be the same size?
  • How do alignment and “no gaps/overlaps” affect measurement?
  • How can a number line show how much longer/shorter one object is than another?

II. Objectives and Standards

Learning Objectives — Students will be able to:

  1. Measure object lengths by iterating same-sized, nonstandard units with no gaps or overlaps.
  2. Align measuring tools properly (start at zero/endpoint) and record results precisely.
  3. Compare two lengths and decide which is longer/shorter; find how much longer using counting or subtraction.
  4. Represent lengths on a number line and use it to justify comparisons.
  5. Choose tools (cubes, paperclips, craft sticks, string) strategically and explain why (MP.5).

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

  • 1.MD.1: Order three objects by length; compare the lengths of 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 end to end; understand that the number of length units is the measurement of the object.
  • Mathematical Practices: MP.5 emphasized (use appropriate tools); MP.6 (precision) and MP.2/MP.3 threaded.

Success Criteria — Student Language

  • I can measure with same-sized units and line up my tool with no gaps/overlaps.
  • I can compare two lengths and tell how much longer/shorter using a number line.
  • I can explain my tool choice and how I knew my measurement was accurate.