Thinkabara

🧮 2nd Grade · Math2.OA.B.2Unit 1: Addition & subtraction fluency within 20

Fact families and missing parts

Google Classroom

🎯 Objective: Students use related facts to find unknowns.

Lesson outline

  1. Triangle flash cards with one corner hidden.
  2. Write fact families.
  3. Partner quiz.
  4. Exit: 6 + ? = 14.

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

2.OA.B.2

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

🏁 Unit goals

  • Add and subtract within 20 fluently using mental strategies
  • Know all sums of two one-digit numbers from memory by year end

✅ 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: Equal groups — the road to multiplication🖨️ Worksheet: Subtraction Within 20📚 All 2nd Grade skills🎮 Learning games⚡ Capy Live class quiz

🗓️ Plan the whole year like this

Add 2nd Grade Math to your free Lesson Planner: enter your timetable once and every period shows the next lesson, skipping weekends and school breaks.

Add to my planner See the year’s sequence

More lessons in “Addition & subtraction fluency within 20”

  1. Strategies we know
  2. Make a ten, both ways
  3. Fact families and missing parts
  4. Fluency practice & goal setting

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