Understanding Hundreds

Subject

Mathematics – Number and Operations in Base Ten

Learning Objective

Students will recognize that one hundred can be composed of 100 ones or 10 tens, and understand the relationship between ones, tens, and hundreds.

Learning Standards

• CCSS.MATH.CONTENT.2.NBT.A.1: Understand that three digits of a three-digit number represent amounts of hundreds, tens, and ones.
• CCSS.MATH.CONTENT.2.NBT.A.1.a: Understand the following as special cases:
  • 100 can be thought of as a bundle of ten tens — called a “hundred.”
• CCSS.MATH.CONTENT.2.NBT.A.2: Count within 1000; skip-count by 5s, 10s, and 100s.

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Key Vocabulary

• Hundred
• Tens
• Ones
• Bundle
• Place value
• Base ten
• Skip counting

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Hook

(10 minutes)

Activity: "Counting Bundles"

• Begin with a quick hands-on warm-up using base-ten blocks (units and ten-rods).
• Show 10 ten-rods and ask students to count the units in each. Then ask, "How many ones in total do these 10 rods make?" Guide students toward realizing it equals 100 ones.
• Introduce the term “hundred” and connect it to this bundle of ten tens.

Purpose: Activate prior knowledge about place value, ones, and tens, and spark curiosity about hundreds.

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Learn (Explore)

Mini-Lesson (I Do) (15 minutes)

• Display a large visual place value chart (ones, tens, hundreds).
• Use base-ten blocks under the document camera or projected on the board:
  • Show 1 one-block, then 10 one-blocks, then bundle 10 one-blocks into 1 ten-rod.
  • Demonstrate 10 tens bundled together to make 1 hundred flat.
  • Write the numbers 1, 10, 100 next to the blocks, emphasizing how each place value position increases by a factor of ten.
• Verbally narrate and emphasize: “100 ones is the same as 10 tens, which is the same as 1 hundred.”

Concrete to Abstract Connection: Students see, touch, and hear stages of counting and bundling.

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Guided Practice (We Do)

(20 minutes)

1. Provide each student with individual sets of base-ten blocks.
2. Call out numbers between 1 to 100 such as 34, 58, 100.
3. Ask students to build the number using ones and tens blocks:
   • Example: For 58, students build 5 tens and 8 ones.
4. Show 10 tens blocks and ask, “How many ones do we have now?”
5. Have students bundle their ten tens into a hundred flat.
6. Lead a discussion, asking questions like:
   • How many ones did it take to make this hundred?
   • Can you show 100 without using hundreds blocks?
7. Practice skip-counting aloud by 10s to 100, then by 100s to 1000.

Teacher Notes: Circulate and assist, correcting grouping errors immediately to reinforce proper place value concept.

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Independent Practice (You Do)

(25 minutes)

Worksheet/Activity: "Build and Write"

• Students receive a worksheet with pictures of base-ten blocks.
• For each image, they write:
  1. The number represented.
  2. How many ones.
  3. How many tens.
  4. Identify if there is a hundred bundle and describe it.
• Extension challenge: Give students numbers under 1000 and have them draw their own base-ten block representation showing hundreds, tens, and ones.

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Closing (Synthesis, Discuss)

(10 minutes)

• Gather students in a circle.
• Recap key points by asking:
  • How many ones make a ten?
  • How many tens make a hundred?
  • How many ones make a hundred?
• Use students’ responses to reinforce:
  • 1 ten = 10 ones
  • 1 hundred = 10 tens = 100 ones
• End with an exciting chant or rap about skip-counting by tens and hundreds.

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Fluency Focus

• Skip-counting by 5s, 10s, and 100s aloud as a class for 3–5 minutes
• Quick “flash card” review showing base-ten blocks or numbers where students shout the value and how many tens/ones/hundreds they see

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Differentiation

For Struggling Learners:

• Use more physical manipulatives.
• Work in pairs to build numbers and verbalize their work.
• Use number lines to visualize skip-counting before base-ten blocks.

For Advanced Learners:

• Challenge by giving 3-digit numbers to build with base-ten blocks.
• Introduce decomposition of 1000 into 10 hundreds.
• Provide word problems involving bundling tens into hundreds.

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Assessment

Formative:

• Observation during guided and independent practice.
• Exit ticket: Students draw and label a number that includes hundreds, tens, and ones.
• Oral questioning during synthesis to check conceptual understanding.

Misconception to Address:

• Students may believe a hundred is just "a big number" and not understand the structured concept of 100 ones or 10 tens.
• Some may think ten tens equals 10, not 100. Reinforce bundling and place value rigorously.

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Materials Needed

• Base-ten blocks for each student (ones, tens, hundreds)
• Place value chart poster/visual
• Worksheets with block images and space to write numbers
• Whiteboard/markers or chart paper

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This detailed lesson plan ensures 2nd graders deeply understand the structure and relationship of ones, tens, and hundreds in a way that is hands-on, interactive, and strictly aligned to Common Core standards 2.NBT.A.1, 2.NBT.A.1.a, and 2.NBT.A.2. The lesson balances concrete learning tools with abstract concepts, frequent formative checks, and differentiation to meet diverse learners’ needs.