Multiplication and Area in the Community Garden
Students will be able to multiply side lengths to find areas of rectangles within the real-world context of designing a community garden.
- Show students images of community gardens or, prior to the lesson, read a book about a community garden, like "City Green" by DyAnne DiSalvo-Ryan.
- Explain: A community garden is an area where people can come together to plant fruits, vegetables, and flowers with their neighbors. Community gardens come in all shapes and sizes.
- Tell students that today they are going to use what they know about multiplication and area to design their own community gardens.
- Review what students have previously learned about finding the area of squares and rectangles. Write their responses on chart paper and display through the duration of the lesson.
Explicit Instruction/Teacher Modeling(5 minutes)
- Using a projector, display a piece of graph paper.
- Draw a rectangle that is 3 square units by 5 square units.
- Review the concept of area. (e.g. “Area is the space inside of a shape. We can measure the area with square units.”)
- Lightly shade or highlight the inside of the rectangle to give a visual of the area.
- Tell students that, to find the area of a square or rectangle, we can multiply the length and width of the shape.
- Write: Area = Length x Width / Area = 3x5 / Area = 15
- Explain that we usually measure a garden in feet, so we are going to imagine that each square unit represents a square foot. Label the sides of the rectangle "3 feet" and "5 feet." Add "square feet" to the area equation so that it reads "Area = 15 square feet."
Guided Practice/Interactive Modeling(15 minutes)
- Hand out a sheet of graph paper to each student.
- Draw and label a rectangle that is 6 feet by 4 feet on the displayed graph paper.
- Instruct students to draw the same rectangle on their graph paper.
- Ask students to turn to a partner and discuss what the area of the rectangle is and how they know. Circulate the class and listen to student discussion.
- Instruct students to write the formula and answer they came up with on their own paper.
- Invite a student or pair of students to share their answer and justification with the class.
- Record the formula and answer on the displayed graph paper (Area = 6 feet x 4 feet / Area = 24 square feet).
- Reframe the answer in context of a community garden. (e.g. “If this were a community garden, how many square feet would neighbors have in which to plant?”)
Independent Working Time(15 minutes)
- Tell students that they will now have the opportunity to create their own community garden.
- Write these guidelines on the board: Your community garden should have an area greater than 24 square feet / label the length and width of your garden using feet / write the formula and find the area of your garden.
- Instruct students to draw a square or rectangle on their graph paper that will represent their community garden.
- Remind them to follow the guidelines on the board and review the guidelines as needed.
- Circulate the room as students work and offer support as needed.
- For students who need more scaffolding, give them a pre-drawn rectangle for their garden and/or instruct them to count the square units inside the shape to find the area, before guiding them to the corresponding multiplication problem.
- For an extra challenge, give students a specific area in which they must ‘build’ a community garden and have them list or draw all the possible dimensions of a garden with that area.
- Make visual observations during independent practice.
- Collect student work to check for understanding.
- In pairs or small groups, have students create a still or moving tableau that shows how to find the area of a rectangle or square. Give students about 3 minutes to work with their group, then invite groups to share their tableaus (e.g. in a group of three, two students may lie on the floor in an L-shape representing length and width, while the third stands or does a movement in the middle representing area). This may be challenging for students to create (and their tableaus will vary) but it will provide an opportunity to assess their understanding of the concept and will also serve as a visual teaching tool for the other students who are watching. See the resources below for additional information about using tableau as assessment.
Review and Closing(7 minutes)
- Sitting in a circle, ask students to share which Studio Habit of Mind they used while designing their own garden (Develop Craft, Engage & Persist, Envision, Express, Observe, Reflect, Stretch & Explore, Understand the World). See resource links for additional information about Studio Habits of Mind.
- Or, alternatively, ask students to share a success or challenge they had while designing their garden.
- As you excuse each student from the circle, ask them to tell you how to find the area of a square or rectangle (length times width).