Grade Level

3rd Grade

Duration

25 minutes

Standards Alignment

Common Core State Standards: Mathematics

• CCSS.MATH.CONTENT.3.NBT.A.2: Fluently add and subtract within 1000 using strategies and algorithms based on place value, properties of operations, and/or the relationship between addition and subtraction.
• CCSS.MATH.CONTENT.3.NBT.A.1: Use place value understanding to round whole numbers to the nearest 10 or 100.

Note: This lesson reinforces place value and two-digit addition, building on prior work with two-digit addition problems and visual counting strategies.

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Learning Objectives

By the end of this lesson, the student will be able to:

1. Decompose two-digit numbers into tens and ones.
2. Add two-digit numbers by first adding tens and ones separately.
3. Use place value charts and visual aids to solve two-digit addition problems confidently and accurately.
4. Explain the strategy aloud, reinforcing both conceptual understanding and math vocabulary (e.g. tens, ones, place value).

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Materials Needed

• Whiteboard and marker
• Place value chart (tens and ones columns) – large visual version
• Base-10 blocks or paper cutouts to represent tens and ones
• Worksheet with 5 two-digit addition problems (designed similar to 41 + 24)
• Counters or small objects (optional for tactile learning)

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Lesson Procedure

1. Introduction and Warm-Up (5 minutes)

• Review previous learning: Briefly revisit two-digit addition problems Brielle practiced earlier (e.g., 41 + 24, 21 + 15).
• Prompt Brielle to share how she solved the problems the last time (through visual counting and place value charts).
• Emphasize the importance of tens and ones in adding two-digit numbers.

Teacher Prompt:
"Can you tell me what the digit 4 means in the number 41? What about the 1?"

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2. Direct Instruction (7 minutes)

• Use a large place value chart on the whiteboard. Write a new problem such as 57 + 26.
• Demonstrate breaking the numbers into tens and ones:
  • 57 = 50 + 7 (5 tens and 7 ones)
  • 26 = 20 + 6 (2 tens and 6 ones)
• Model adding tens first (50 + 20 = 70), then ones (7 + 6 = 13).
• Discuss regrouping (if needed): since 13 is more than 10, it can be rewritten as 10 + 3, so add 10 to tens column (70 + 10 = 80) and write 3 in ones column.
• Write out the full addition process clearly on the whiteboard.
• Use base-10 blocks to visually represent tens and ones, showing regrouping if appropriate.

Encourage Brielle to verbalize each step to reinforce understanding.

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3. Guided Practice (8 minutes)

• Present 3 two-digit addition problems from the worksheet one at a time (e.g., 34+15, 62+27, 45+38).
• Have Brielle:
  • Break numbers into tens and ones.
  • Use the place value chart to add tens and ones.
  • Apply regrouping if necessary.
• Guide Brielle with prompting questions:
  • "What are the tens in both numbers?"
  • "How do you add these tens together?"
  • "What do you do if your ones add up to more than 9?"
• Use base-10 blocks or counters if she needs additional support.

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4. Independent Practice & Explanation (4 minutes)

• Provide Brielle with 2 additional problems and ask her to solve independently using the place value chart and materials.
• After solving, Brielle explains her steps aloud, focusing on how she grouped tens and ones and if she had to regroup.

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5. Assessment & Closing (1-2 minutes)

• Ask Brielle a reflection question to assess conceptual understanding:
  "Why is it helpful to add tens and ones separately when working with two-digit numbers?"
• Provide positive feedback highlighting strengths in using place value and encouraging use of math vocabulary.
• Remind Brielle that mastering these strategies will help with larger numbers later on!

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Differentiation Tips

• If Brielle grasps concepts quickly, introduce a small challenge with adding three two-digit numbers (e.g., 21 + 35 + 42) in the same way.
• If struggling, use more tactile materials like base-10 blocks or draw pictures to make tens and ones more concrete.
• Encourage pairing words with numbers for students needing cross-curricular reinforcement (e.g., spelling number words).

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Extensions

• For further practice, incorporate word problems requiring two-digit addition with place value strategies.
• Introduce rounding to the nearest ten after mastery, tying back to standard CCSS.MATH.CONTENT.3.NBT.A.1.

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Summary

This 25-minute lesson builds directly on Brielle’s prior work with two-digit addition and place value by strengthening her understanding of decomposing numbers into tens and ones, applying regrouping, and solving problems using visual and tactile methods. It aligns with the Common Core standards for grade 3 and integrates verbal explanation to deepen comprehension and math communication skills.