Building Number Sense

Grade Level: 2nd Grade

Subject: Math – Place Value and Word Problems

Duration: 45 Minutes

Curriculum Area and Level:
Louisiana Student Standards for Mathematics (LSSM) –

• 2.NBT.A.1: Understand that the three digits of a three-digit number represent amounts of hundreds, tens, and ones; e.g., 706 equals 7 hundreds, 0 tens, and 6 ones.
• 2.OA.A.1: Solve word problems that call for addition and subtraction within 100, with unknowns in all positions.

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Objectives

By the end of this lesson, students will:

1. Identify and represent hundreds, tens, and ones in three-digit numbers.
2. Solve multi-step word problems by applying knowledge of place value.
3. Validate and affirm diverse learning strategies while building and bridging mathematical understanding to real-world problems.

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Materials Needed

• Base-ten blocks (for visualizing hundreds, tens, and ones)
• Whiteboards and markers (or journals for students to write answers)
• A teacher-prepared "word problem spinner" (made with card stock for various problem scenarios: addition, subtraction within 100, and place value exploration)
• Place value charts (printable or drawn on paper)
• Envelopes with small challenge cards for peer group work
• Exit slips asking a reflective question on place value

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Lesson Breakdown

Quantity: 10 Minutes – Warm-Up Activity

1. Engagement & Validation:
   Start by relating place value to something recognizable to students’ lives. Say:
   “Imagine, your family is buying groceries for a party. You count hundreds of jellybeans, tens of cupcakes, and just a few apples! How would you write down the numbers so they look neat?”
   This validates the connection between abstract maths and relatable scenarios like counting items.

2. Hands-On Exploration:

   • Distribute base-ten blocks to each group of students.
   • Call out numbers (e.g., 342, 109, 574) and have students physically build the numbers using hundreds, tens, and ones blocks. Begin with simpler numbers (3-digit) and progress gradually.
   • Ask students to share unique strategies they use to "count" the blocks and write them on their whiteboards. This encourages metacognition and affirms student approaches.

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Quality: 15 Minutes – Word Problem Practice

1. Interactive Word Problem from the “Word Problem Spinner”:

   • Spin the word problem spinner to generate problems that connect to real life (e.g., “Chloe needs 56 balloons for a party but has 24 now. How many more does she need?”).
   • Students first solve one problem independently on their whiteboards using any strategy they prefer: base-ten blocks, quick addition, or writing equations.
   • Peer-validate the work: Pair students, and have them compare answers. Ask “Did we solve it differently? Is one way faster or clearer for you?”

2. Affirmation of Diverse Strategies:
   Walk around and acknowledge different problem-solving approaches (e.g., a drawing approach vs. symbolic addition). This creates an inclusive environment where differences are affirmed.

3. Let’s Make It Harder!
   Build additional, trickier word problems to scaffold learning while bridging to abstract thinking:

   • Example: “Ms. Ramos wants to buy 245 candies for her second-grade class. She has filled three bags with 78 candies in each. How many does she need to reach her total?”

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Strategy: 15 Minutes – Building and Bridging Place Value Mastery

1. Peer Work: Place Value Matching Challenge

   • Divide students into small groups of 3-4.
   • Hand out envelopes with place value challenge cards containing three types of activities:
     a) Matching three-digit numbers to expanded forms (e.g., 453 = 400 + 50 + 3).
     b) Identifying the missing value in a place value chart.
     c) Rearranging mixed-up digits like 304 to create the "largest" and "smallest" possible numbers.

2. Real-World Bridge: Have each group pretend they are part of a zoo counting animals (e.g., Group 1 counts giraffes: 243, hippos: 315, and elephants: 126). How can they “write” the totals using place value concepts, expanded forms, or solving how many total animals their zoo has altogether?

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Reflection: 5 Minutes – Exit Slip

Hand out an exit slip with the following reflection question:

-“How did understanding hundreds, tens, and ones help you solve a problem today? Can you teach someone else what you just learned?”

Students complete this individually, reinforcing self-assessment and their ability to articulate learning outcomes.

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Reflection: Teacher’s Assessment of Lesson Impact

• What worked?
  Did students actively engage in peer-validation during problem-solving?
• What needs adjusting?
  Were word problems appropriately challenging for the majority of learners?
• How can I improve bridging?
  How can the next lesson build more effectively towards higher-order thinking while affirming diverse cultural and cognitive approaches?

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Addressing the Uncertain Question:

How can CLR (Culturally and Linguistically Responsive) activities be integrated into independent/group work?

• Validation can occur by creating word problems tied to students’ diverse cultural contexts (e.g., counting tamales for a family dinner or measuring distances to a soccer field).
• Build bridges from known responsibilities (like helping family with chores, shopping, or preparing for events) to abstract place value concepts.
• Encourage group work to empower peer-affirmation of cultural relevance during real-world problem-solving.

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Extension Idea (Optional for Homework):

Write your own word problem about place value using friends, family, or hobbies. Bring it in for the class tomorrow to solve together!