Thinkabara

🧮 2nd Grade · Math2.NBT.B.5Unit 5: Subtracting within 100

Regrouping a ten

Google Classroom

🎯 Objective: Students subtract when they need to break a ten (52 − 27).

Lesson outline

  1. Build 52; not enough ones — trade a ten.
  2. Record step by step.
  3. Partner practice.
  4. Exit: 61 − 38.

Lesson 2 of 5 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

2.NBT.B.5

Common Core State Standards for Mathematics, Grade 2 — typical US scope & sequence

🏁 Unit goals

  • Subtract two-digit numbers using place value strategies
  • Check subtraction with addition

✅ 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: Add & subtract within 100🖨️ Worksheet: Two-Digit Addition Within 100🖨️ Worksheet: Two-Digit Subtraction Within 100📚 All 2nd Grade skills🎮 Learning games⚡ Capy Live class quiz

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More lessons in “Subtracting within 100”

  1. Subtracting tens and ones
  2. Regrouping a ten
  3. Counting up to subtract
  4. Check with addition
  5. Subtraction word problems

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