Counting and Grouping

Overview

Grade Level: 2nd Grade
Subject: Mathematics
Duration: 30 minutes
Curriculum Area: Number Sense
California Content Standard: N07.02, N07.03

Objectives

• Students will learn to count objects in sets using groups of 10s and 1s.
• Students will record numbers as 2-digit numerals under the headings of 10s and 1s.
• Students will describe 2-digit numbers in two ways.

Materials

• Plastic counters or blocks (enough for each group)
• Large chart paper and markers
• Small whiteboards and dry erase markers for each student
• Number cards (1-9 and 10-90 by tens)

Lesson Structure

Introduction (5 minutes)

1. Greet the Class: Welcome students and tell them they are going to play a fun game with numbers today.

2. Engage: Ask the class if anyone has ever counted something big, like a collection of toys or blocks. Ask which is easier: counting by ones or by groups of tens?

3. Objective Review:

   • Explain that they will learn how to count objects in groups of tens and ones.
   • They will also learn how to describe numbers in two different ways.

Activity 1: Counting by 10s and 1s (10 minutes)

1. Grouping Exercise:

   • Divide students into small groups of 4-5.
   • Distribute a set of counters to each group (at least 40 per group).

2. Guided Practice:

   • Ask each group to count their counters by making groups of 10.
   • Have students count the leftover counters as ones.
   • Demonstrate on the board using the headings "10s" and "1s".

3. Recording:

   • Ask groups to write the numeral in their notebooks under the headings "10s" and "1s".
   • Example: If a group has 3 groups of 10 and 4 extra counters, they write 34.

Activity 2: Describing Numerals in Two Ways (10 minutes)

1. Whole Group Sharing:

   • Select a few groups to share their numbers and how they counted on the board.

2. Visualization:

   • Show a number card, e.g., '24'.
   • Demonstrate and explain: "24 can be seen as 2 tens and 4 ones or 24 ones."

3. Interactive Participation:

   • Use number cards. Hold one up and ask a student to come and describe the number in two ways.
   • Encourage the use of whiteboards to practice with different numbers.

Wrap-Up (5 minutes)

1. Review Questions:

   • Ask students if they know why grouping by tens can help with counting.
   • Have them describe a number of their choice in two ways.

2. Reflection:

   • Ask students to think about a time they might use counting by tens and ones outside of school.

3. Extension Suggestion:

   • Challenge students to find objects at home to count using the same method.

Assessment

• Observe and take notes as students work in groups.
• Review students' recordings of numbers on their whiteboards for accuracy.
• Listen to sharing and participation during number description.

Teacher's Note

• Walk around during activities to provide guidance and correct misconceptions.
• Encourage collaboration and sharing of ideas within groups.
• Celebrate unique strategies or explanations offered by students to enhance understanding.

By utilizing engaging hands-on activities coupled with peer interaction, this lesson plan aims to solidify understanding of counting and describing 2-digit numbers in a fun and meaningful way.