Thinkabara

🧮 1st Grade · Math1.MD.A.2Unit 9: Measuring length

Why same-size units?

Google Classroom

🎯 Objective: Students see why units must be the same size to compare measurements.

Lesson outline

  1. Measure with a mix of big and small clips: what went wrong?
  2. Compare results using the same unit.
  3. Re-measure with one kind of unit.
  4. Exit: explain in a sentence.

Lesson 3 of 4 in this unit. In the Lesson Planner this lesson takes 1–3 class periods depending on your timetable: day 1 introduce & model, then practice, small-group reteach and a quick check.

📐 Standard

1.MD.A.2

Common Core State Standards for Mathematics, Grade 1 — typical US scope & sequence

🏁 Unit goals

  • Order three objects by length
  • Measure length with same-size units, with no gaps or overlaps

✅ Check for understanding

End with the exit ticket in the outline. Sort answers into got it / almost / not yet and start the next lesson with a 5-minute reteach for the “not yets”.

Practice & resources on Thinkabara

🎯 Practice: Measure lengths & tell time📚 All 1st Grade skills🎮 Learning games⚡ Capy Live class quiz

🗓️ Plan the whole year like this

Add 1st Grade Math to your free Lesson Planner: enter your timetable once and every period shows the next lesson, skipping weekends and school breaks.

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More lessons in “Measuring length”

  1. Order by length
  2. Measure with units
  3. Why same-size units?
  4. Measurement stories

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