Comparing Two-Digit Numbers

Objective

To enable 1st-grade students to compare two-digit numbers by understanding the value of tens and ones, and to correctly use >, =, and < symbols.

Curriculum Standards

• Common Core State Standards for Mathematics, Grade 1
• Number and Operations in Base Ten: Understand place value. Specifically, CCSS.MATH.CONTENT.1.NBT.B.3 - Compare two two-digit numbers based on meanings of the tens and ones digits, recording the results of comparisons with the symbols >, =, and <.

Materials

• Number cards (sets of two-digit numbers, e.g., 14, 57, 83, etc.)
• Base ten blocks (ten rods and unit cubes)
• Whiteboard and markers
• Comparison symbols cards (>, =, <)
• Math journals or sheets of paper
• Pencils and crayons

Duration

20 minutes

Lesson Outline

1. Introduction (3 minutes)

• Briefly explain the goal of the lesson: to learn how to compare two-digit numbers using the value of tens and ones.
• Review the symbols >, =, and < and what they represent.

2. Direct Instruction (5 minutes)

• Display two two-digit numbers using number cards (e.g., 34 and 47).
• Demonstrate how to break each number into tens and ones:
  • 34: 3 tens and 4 ones
  • 47: 4 tens and 7 ones
• Use base ten blocks to visually represent each number. Show three rods (tens) and four cubes (ones) for 34, and four rods (tens) and seven cubes (ones) for 47.
• Ask students to count the tens first. Discuss which number has more tens and how it helps in deciding which number is greater.
• Use the comparison symbols to show that since 47 has more tens than 34, thus 34 < 47.

3. Guided Practice (5 minutes)

• Divide students into pairs and give each pair a set of number cards and base ten blocks.
• Instruct students to randomly draw two number cards.
• Each pair uses the base ten blocks to represent the numbers, count the tens first, then the ones, and orally decide which number is greater or if they are equal.
• Each pair records their comparison using the correct symbol on the whiteboard or paper.

4. Hands-On Activity (5 minutes)

• Turn the comparisons into a friendly game: "Numbers Face-Off."
• Arrange students in a circle and give each child one number card.
• Two students stand in the middle and compare their numbers using base ten blocks.
• They place the right comparison symbol between the numbers and explain their reasoning to the class.
• Rotate students so each child gets a turn.
• Encourage creativity in explaining their reasoning - students can describe their thought process or even draw a quick sketch.

5. Closure (2 minutes)

• Gather the students back together and briefly discuss what they learned.
• Ask one or two volunteers what was easy or challenging about using tens and ones to compare numbers.
• Praise students for their efforts and clarify any lingering confusion.

Assessment

• Observe students during the "Numbers Face-Off" game to assess understanding.
• Collect the math journals or papers used to ensure students correctly recorded comparisons.

Differentiation

• For advanced students, introduce three-digit numbers if appropriate.
• Provide additional support by working with smaller numbers (e.g., comparing two numbers like 10 and 12) or using visuals/pictorial representations for students requiring extra assistance.
• Encourage peer support by pairing struggling students with those who grasp the concept more quickly.

This lesson plan utilizes physical, visual, and kinesthetic learning styles, making the abstract concept of number comparison concrete and engaging for young learners.