Explore the area
 

Preparation:

• Prepare the ruler and the plates needed for the lesson (see the heading "Things you need").

Things you need:

1. Plate No.: 1, (4), 5, 8, (9), 14

2. Ruler

3. Paper and pencil for calculations

Purpose:

Students will:

1. Develop their knowledge of geometry and area.

2. Practice communicating and collaborating in a group.

3. Practice problem solving by measuring and calculating area.

Introduction (approx. 10 min):

Demonstrate how to measure the length and width of a disk using a ruler. Explain that the area is calculated by multiplying the length by the width.

Implementation (approx. 20 min):

1. Divide the class:

   • Divide the students into smaller groups and give each group 3 flat pieces.

2. Measure the discs: Have students use the ruler to measure the length and width of their piece.

3. Calculate the area: Help students multiply the length and width to calculate the area of the piece.

4. Compare: Ask students to compare their results with each other and see which piece has the largest and smallest area.

Conclusion (approx. 10 min):

1. Presentation:

   • Have each group present their results and explain how they calculated the area of their piece.

2. Reflection:

   • Discuss any difficulties and how different groups came up with their solutions.

Curriculum connection:

Speech perception and speech use:

• Reasonableness assessment in estimates and calculations.

Algebra:

• Mathematical equalities and how the equal sign is used to draw simple equations.

Geometry:

• Comparisons and estimates of quantities.

Problem solving:

• Strategies for solving mathematical problems in student-centered situations.

• Formulation of mathematical questions based on everyday situations.

Challenge:

Calculate the area of piece 4 and piece 9 which are triangles

Results for plates (in cm²):

Piece No. Area (cm²)
1,784
4,338
5,532
8,392
9,299
14,196