Adding and Subtracting Fun

Curriculum Connection

Ontario Curriculum Standard: Mathematics | Number | Grade 1
Specific Expectation: Solving Addition and Subtraction Problems (up to 20)

Objective

By the end of this lesson, students will be able to solve basic addition and subtraction problems using manipulatives and mental math strategies.

Materials

• Counting blocks or small objects (e.g., buttons, beads)
• Whiteboard and markers
• Prepared number cards (0-20)

Introduction (2 minutes)

1. Engagement: Start with a quick story. "Imagine today we're going to help a squirrel gather nuts. The squirrel wants to know how many nuts he has and how many he can share with his friends."
2. Objective Explanation: "Today, we're going to learn how to add and subtract numbers up to 20 using our counting blocks. This will help us help our squirrel friend!"

Activity (5 minutes)

1. Demonstration (3 minutes):
   a. Addition:
   • Place 3 counting blocks on the table. Ask, "If the squirrel finds 2 more nuts, how many nuts does he have altogether?"
   • Physically add 2 more blocks and count together with students to find the total (5). b. Subtraction:
   • Use a number such as 5 blocks and say: "The squirrel decides to share 2 nuts with his friend. How many will he have left?"
   • Remove 2 blocks and count the remaining blocks together (3).
2. Guided Practice (2 minutes):
   • Student Involvement: Break students into small groups (5 groups with 4 students each) and give each group 10 counting blocks.
   • Task: Ask each group to come up with one addition and one subtraction problem similar to the ones demonstrated using their blocks.
   • Teacher Circulation: Move around the room, prompting with questions like, "How did you find your answer?"

Closing (3 minutes)

1. Quick Sharing: Ask one group to volunteer to share their addition problem and another group to share their subtraction problem.
2. Review: "Today, we helped the squirrel add and share nuts by adding and removing blocks. Remember, when we add, the number gets bigger, and when we subtract, the number gets smaller."
3. Exit Ticket: Before lining up, each student picks a number card between 0-20 and states whether they will add or subtract a number (e.g., “I pick 7, and I’ll subtract 2 to get 5”).

Tips for Teachers

• Differentiation:
  • For advanced students, increase the number range or introduce basic word problems.
  • For students needing support, pair them with a buddy or reduce the number range.
• Engagement: Use animated voices or props (e.g., a squirrel puppet) to maintain interest.

Follow-Up

• Extend Learning: In the following lesson, incorporate addition and subtraction within context by using simple story problems.
• Home Connection: Send home a mini worksheet for students to practice with a family member.

This lesson plan creatively engages students with stories and hands-on activities while ensuring alignment with the Ontario curriculum's specific expectations for mathematics in Grade 1.