Lessons

Design & Build a Seed Sorter

Assortment of seeds

Assortment of seeds (cynoclub, iStockphoto)

Assortment of seeds

Assortment of seeds (cynoclub, iStockphoto)

Biology,  Science,  Technology & Engineering
Let's Talk Science

How does this align with my curriculum?

Curriculum Alignment
NS 7 Science Grade 7 (2020) Learners will construct a structure in response to a design challenge.
NS 8 Science Grade 8 (2020) Learners will construct a device that utilizes hydraulics or pneumatics.
MB 3 Science Grade 3 (1999) Cluster 1: Growth and Changes in Plants
NB 3 Science 3: Our Local Environment October (2019) Plants
NL 3 Science 3 (2017) Unit 4: Plant Growth and Changes
NL K Exploring My World (2010) A Closer Look at Plants
NU 3 K-6 Science and Technology Curriculum (NWT, 2004) Life Systems: Growth and Changes in Plants
QC Elementary Cycle 2 Science and Technology, Elementary Living Things
SK 3 Science Grade 3 (2011) Life Science – Plant Growth and Changes (PL)
ON 3 Science and Technology, Grade 3 (2022) Strand B: Growth and Changes in Plants
NT 3 K-6 Science and Technology Curriculum (NWT, 2004) Life Systems: Growth and Changes in Plants
AB 4 Science 4 (2023) Living Systems: Understandings of the living world, Earth, and space are deepened by investigating natural systems and their interactions.
AB 5 Science 5 (2023) Living Systems: Understandings of the living world, Earth, and space are deepened by investigating natural systems and their interactions.
NS 3 Science 3 (2019) Life Science: Plants
AB 2 Science 2 (2023) Living Systems: Understandings of the living world, Earth, and space are deepened by investigating natural systems and their interactions.

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Students will work collaboratively to design and build a device that is able to sort seeds by size.

Overview

In this Design & Build challenge, students will work collaboratively towards a common goal of constructing a sorting device that will assist students to sort seeds by size.

Timing
45-60 minutes

Setting the Stage

Prior Skills and Knowledge

To successfully participate in this Design & Build, students should be able to use basic cutting tools and fasteners and have a basic understanding of how to sort by size.

Context

Seeds are an important part of the natural world and the business of agriculture in Canada. Many kinds of seeds become food for animals and humans. Some seeds are used to produce more crops and grow more food in following years. Canadian farmers also sell their crops as seed to other farmers all around the world to produce food and animal feed.

Before crops are sold, they are graded based on the quality of the seeds and the amount of weed seeds in the crop. (It’s a bit like getting a mark at school!) A crop with fewer weed seeds and larger, more uniform seeds gets a better grade because bigger seeds usually produce stronger new plants. Seeds can be used for different purposes (seed stock, human food, processed foods and animal feed, etc). Crop sellers must make sure they have the best seeds for the purpose they want to sell them for. That's why it's important to sort seeds. 

In this Design & Build challenge, students will work collaboratively towards a common goal of constructing a sorting device that will assist students in sorting seeds by size.

This design and build could begin from:

  • exploring photos of crops being harvested. Discuss using questions such as:
    • “Why does a grain company need to sort seeds? How do they do this?” 
    • “In a huge field there might be some weeds that grow as well as the crop. How do you think grain companies remove weed seeds from the crop seeds?”
Corn being harvested using a corn picker
Corn being harvested using a corn picker (Source: Wikimedia Images via Pixabay).
  • exploring real ears of corn, heads of wheat or barley or soybean pods. Discuss using questions such as:
    • “Do all the seeds on this corn cob/wheat head/soybean pod look the same? Are all seeds of a crop the exact same size?”
    • “Would you want to eat all of these kernels/seeds?”
Clockwise from top left are rice, oats, soybeans and corn
Clockwise from top left are rice, oats, soybeans and corn (Source: Tongpradit Charoenphon via Pixabay, Annette Meyer via Pixabay, Julio César García via Pixabay).
  • Reading a book such as The Empty Pot by Demi. Discuss using questions such as:
    • “How does the emperor choose which person will replace him as emperor?” 
    • “What do you think are the qualities of a good emperor?”
    • “What was the problem with the seeds the emperor gave to the children to plant? What was the emperor really trying to prove?”
    • “Was the emperor successful at finding the best kind of new emperor?”
    • “We sometimes hear the expression – ‘he/she is a good seed’ or ‘he/she is a bad seed’. What do you think that means?”
Cover of The Empty Pot by Demi
Cover of The Empty Pot by Demi (Source: Open Library).

Design Criteria

As a class, students brainstorm criteria that their prototype seed sorter must meet. Educators may choose to add other criteria that are curriculum-specific. For example, educators may instruct students to use joiners/fasteners, specific measurements, specific materials, etc. 

Design criteria examples:

  • The seed sorter will sort seeds into three different sizes
  • The seed sorter must use at least one type of fastener
  • The seed sorter cannot require outside force (e.g., shaking it) to work

Details

  • Seeds of three distinct sizes for sorting (e.g., large: lima beans/kidney beans; medium: soybeans/popcorn; small: tomato seeds/millet/rice/barley) – alternately, use commercial bird seed
  • Funnels of different sizes
  • Paper or Styrofoam cups, varied sizes
  • plastic flat-bottomed containers or trays to catch and contain seeds
  • construction paper and/or cardstock
  • paper punches or craft punches of different sizes
  • other materials such as craft sticks, drinking straws, string
  • tools and fasteners such as tape, glue, other fasteners
  • scissors
Suggested materials for seed sorters
Suggested materials for seed sorters (© 2019 Let's Talk Science).
  • Collect an assortment of recycled and new materials that students will use to construct the prototype seed sorter. The materials list above is only a suggested list.
  • Set up material sourcing stations, organized by type of material. Alternatively, organize an assortment of materials to be provided.
  • Source and combine seeds for sorting. 
  • If there are students with allergies or concerns about using food seeds for this challenge, consider substituting beads of 3 different sizes. Check that the smallest beads will be able to go through one of the available funnels.
Mixed seeds ready for sorting
Mixed seeds ready for sorting (©2018 Let’s Talk Science).


 

Students develop Design & Build skills as they design, build and test a seed sorter that will separate seeds into at least three different sizes.

Students will follow the steps of the Design & Build process:

  • identify the problem to be solved/need to be met 
  • brainstorm criteria that the prototype must meet
  • share their questions and ideas for a solution to the problem/need
  • discuss the pros and cons of each in order to select a potential solution to test
  • visualize what the solution might look like and make design sketches based on their visualizations 
  • identify the tasks or key steps involved in developing the solution (the design plan)
  • make decisions about tools and materials that will be needed 
  • build/develop the design idea based on their sketches and design plan 
  • test their prototypes based on the design criteria
  • modify the prototype and retest it against the design criteria as necessary 
  • reflect on their results and identify things that could be done to improve their prototypes

Observe and document, using anecdotal comments, photos and/or video recordings, student’s ability to:

  • Work Collaboratively –  students work collaboratively to complete a task and evaluate their group processes throughout the Design & Build process
  • Generate Ideas –  students use idea generation skills and strategies, such as brainstorming, to identify possible solutions as well as make decisions about the pros and cons of each solution
  • Communicate –  students communicate their thinking and learning in words, sketches, photos, videos, etc. (e.g., in identifying the problem, in design plans that include 2D design sketches and key design steps/tasks, in lists of materials/equipment/tools)
  • Work Safely –  students demonstrate safe practices when using a variety of tools and materials while prototyping
  • Test – students use skills of observing and recording data as they test their prototypes
  • Reflect – students reflect on the results of their prototype testing and suggest things that they might do differently to improve their prototypes
Students:
Saying, Doing, Representing		 Educator:
Interactions: Responding, Challenging
Students identify and refine the problem to be solved/need to be met.
  • “What does sorting mean?”
  • “How could you sort something without using your hands?”
Students brainstorm and record criteria for the seed sorter.
  • “What should the seed sorter be able to do? What design criteria must your prototype meet?”
  • “What forces acting on your seeds could help in the sorting process (e.g. gravity)?”
  • “What words could we use to describe some of the attributes/qualities the seed sorter must have to be effective?" (e.g., accurate, easy to use, fast, etc.)
  • “Have you ever used or seen any other tools or machines that help separate things? What did they look like?”
Students visualize what the solution might look like and make design sketches based on their visualizations.
  • “Why do engineers label all the parts of their design drawings?”
  • “How will you represent each part of your seed sorter prototype in the design sketch?”
  • “How does your seed sorter design plan meet the design criteria?”
Students make observations and decisions about the available tools and materials.
  • “How could the materials we have here be used to sort seeds of different sizes?”
  • “What tools will you need to build the seed sorter you have designed?”
Students build/develop and test the design idea based on their sketches and design plan (create the “prototype”).
  • “How will you test your seed sorter?” 
  • “Which of the design criteria does your prototype meet? Which ones does it not yet meet? Why do you think this happened?”
  • “Does your seed sorter prototype sort the seeds the way you planned? Why or why not?”
Students modify the prototype and retest it against the design criteria as necessary.
  • “What problems did you have when you re-tested your seed sorter?”
  • “What changes in your model might improve your results?”
  • “How would it change your design if you had to sort five sizes of seeds?”
Students reflect on the results of their testing and identify things that could be done differently in the future.
  • “What materials worked best? What materials did not work as well?”
  • “How is your seed sorter like those of your classmates? How is it different? Why do you think that is?”
  • “What have you learned about how solid materials can be sorted by doing this challenge?”
  • “How did your team work together to solve the problem? What challenges did your team have in working together?”

 

Literacy

  • Ask questions (e.g. “Why do we need to sort seeds? How can technology help us do these tasks?”)
  • Communicate thoughts, feelings and ideas. For example:
    • brainstorm unique ways to use materials to sort the seeds 
    • propose improvements to the initial seed sorter design
    • present results of the Design & Build process
    • discuss other seed-related technologies that are involved in farming and agriculture
  • Use a variety of forms (e.g., oral, written, graphic, multimedia) to communicate with different audiences and for a variety of purposes (e.g., to make a prototype model of a seed sorter)

Mathematical Thinking

  • Measure the diameter of the seeds (in millimetres) in preparation for designing and building the seed sorter
  • Using spatial reasoning and sequencing when designing and constructing the seed sorter

Visual Arts

  • Sketching, representing and modeling the seed sorter prototype

Computational Thinking: Abstraction

  • Use spatial reasoning and sequencing when designing and constructing the seed sorter (e.g., draw a concept design of a seed sorter)
Sample seed sorters created by educators during a Let’s Talk Science professional learning session
Sample seed sorters created by educators during a Let’s Talk Science professional learning session (©2018 Let’s Talk Science).

 

If your students are interested in learning more, the following may provoke their curiosity:

  • Conduct another inquiry to compare the germination process in different plant species from the seeds that have been sorted in this Design & Build. Is there any connection between the rate of germination and the size of seeds? (For example, do small seeds germinate faster than large seeds?)
  • Indigenous cultures have legends and traditional agricultural customs that involve growing crops together, as opposed to monoculture (single-species crops). The Three Sisters Legend is based on the practice of growing corn, beans and squash together. The corn supports the growing beans and the leaves of the squash cover the ground around the base of the plants to stop weeds from growing. Have students watch a video of The Three Sisters Legend without telling them which plants each of the girls represents.
  • Participate in Tomatosphere™, operated by Let’s Talk Science, and learn whether tomato seeds germinate differently if they have been to space.
Germinating soybeans
Germinating soybeans (Source: <a href="https://pixabay.com/users/jcesar2015-1295189/?utm_source=link-attribution&utm_medium=referral&utm_campaign=image&utm_content=13…">Julio César García</a> via <a href="https://pixabay.com/photos/plants-soybean-soy-nature-1331667/">Pixabay</a>).
Screen capture from The Three Sisters Legend
Screen capture from <a href="https://www.youtube.com/watch?v=Fx9CDVkN9xU">The Three Sisters Legend</a> (Source: <a href="https://www.youtube.com/watch?v=Fx9CDVkN9xU">Widdifield Courtyard on YouTube</a>).

 

Cover of The Empty Pot by Demi
Cover of The Empty Pot by Demi (Source: <a href="https://openlibrary.org/books/OL3970809M/The_empty_pot">Open Library</a>).

The Empty Pot
By Demi
When Ping admits that he is the only child in China unable to grow a flower from the seeds distributed by the Emperor, he is rewarded for his honesty.
ISBN 0962929859

The Three Sisters Legend (2015) Widdifield Courtyard -- Animated video (3:06 min.) of the Iroquois legend of The Three Sisters garden. 

Design & Build a Seed Saver (Lessons)

Students will work collaboratively to design and build a structure that will protect a seed from the elements.

Seed Dispersal (Lessons)

Students develop and apply the skills of observing, comparing, contrasting, sorting and classifying, to investigate how seeds move from place to place.

Design & Build a Travelling Seed (Lessons)

Students will work collaboratively to design and build models of seeds that can travel as far as possible.

Tomatosphere™ (Website)

How does outer space affect plants and seeds? Join Tomatosphere™, a free program where Kindergarten to Grade 12 students use "space" tomato seeds to learn about plants in space, right here on Earth. Tomatosphere™ engages students in real scientific processes that teach and reinforce inquiry skills while they explore concepts related to plants, space, careers, nutrition and agriculture.

Materials

  • Seeds of three distinct sizes for sorting (e.g., large: lima beans/kidney beans; medium: soybeans/popcorn; small: tomato seeds/millet/rice/barley) – alternately, use commercial bird seed
  • Funnels of different sizes
  • Paper or Styrofoam cups, varied sizes
  • plastic flat-bottomed containers or trays to catch and contain seeds
  • construction paper and/or cardstock
  • paper punches or craft punches of different sizes
  • other materials such as craft sticks, drinking straws, string
  • tools and fasteners such as tape, glue, other fasteners
  • scissors
Suggested materials for seed sorters
Suggested materials for seed sorters (© 2019 Let's Talk Science).

Preparation

  • Collect an assortment of recycled and new materials that students will use to construct the prototype seed sorter. The materials list above is only a suggested list.
  • Set up material sourcing stations, organized by type of material. Alternatively, organize an assortment of materials to be provided.
  • Source and combine seeds for sorting. 
  • If there are students with allergies or concerns about using food seeds for this challenge, consider substituting beads of 3 different sizes. Check that the smallest beads will be able to go through one of the available funnels.
Mixed seeds ready for sorting
Mixed seeds ready for sorting (©2018 Let’s Talk Science).


 

What to Do

Students develop Design & Build skills as they design, build and test a seed sorter that will separate seeds into at least three different sizes.

Students will follow the steps of the Design & Build process:

  • identify the problem to be solved/need to be met 
  • brainstorm criteria that the prototype must meet
  • share their questions and ideas for a solution to the problem/need
  • discuss the pros and cons of each in order to select a potential solution to test
  • visualize what the solution might look like and make design sketches based on their visualizations 
  • identify the tasks or key steps involved in developing the solution (the design plan)
  • make decisions about tools and materials that will be needed 
  • build/develop the design idea based on their sketches and design plan 
  • test their prototypes based on the design criteria
  • modify the prototype and retest it against the design criteria as necessary 
  • reflect on their results and identify things that could be done to improve their prototypes

Assessment

Observe and document, using anecdotal comments, photos and/or video recordings, student’s ability to:

  • Work Collaboratively –  students work collaboratively to complete a task and evaluate their group processes throughout the Design & Build process
  • Generate Ideas –  students use idea generation skills and strategies, such as brainstorming, to identify possible solutions as well as make decisions about the pros and cons of each solution
  • Communicate –  students communicate their thinking and learning in words, sketches, photos, videos, etc. (e.g., in identifying the problem, in design plans that include 2D design sketches and key design steps/tasks, in lists of materials/equipment/tools)
  • Work Safely –  students demonstrate safe practices when using a variety of tools and materials while prototyping
  • Test – students use skills of observing and recording data as they test their prototypes
  • Reflect – students reflect on the results of their prototype testing and suggest things that they might do differently to improve their prototypes

Co-constructed Learning

Students:
Saying, Doing, Representing		 Educator:
Interactions: Responding, Challenging
Students identify and refine the problem to be solved/need to be met.
  • “What does sorting mean?”
  • “How could you sort something without using your hands?”
Students brainstorm and record criteria for the seed sorter.
  • “What should the seed sorter be able to do? What design criteria must your prototype meet?”
  • “What forces acting on your seeds could help in the sorting process (e.g. gravity)?”
  • “What words could we use to describe some of the attributes/qualities the seed sorter must have to be effective?" (e.g., accurate, easy to use, fast, etc.)
  • “Have you ever used or seen any other tools or machines that help separate things? What did they look like?”
Students visualize what the solution might look like and make design sketches based on their visualizations.
  • “Why do engineers label all the parts of their design drawings?”
  • “How will you represent each part of your seed sorter prototype in the design sketch?”
  • “How does your seed sorter design plan meet the design criteria?”
Students make observations and decisions about the available tools and materials.
  • “How could the materials we have here be used to sort seeds of different sizes?”
  • “What tools will you need to build the seed sorter you have designed?”
Students build/develop and test the design idea based on their sketches and design plan (create the “prototype”).
  • “How will you test your seed sorter?” 
  • “Which of the design criteria does your prototype meet? Which ones does it not yet meet? Why do you think this happened?”
  • “Does your seed sorter prototype sort the seeds the way you planned? Why or why not?”
Students modify the prototype and retest it against the design criteria as necessary.
  • “What problems did you have when you re-tested your seed sorter?”
  • “What changes in your model might improve your results?”
  • “How would it change your design if you had to sort five sizes of seeds?”
Students reflect on the results of their testing and identify things that could be done differently in the future.
  • “What materials worked best? What materials did not work as well?”
  • “How is your seed sorter like those of your classmates? How is it different? Why do you think that is?”
  • “What have you learned about how solid materials can be sorted by doing this challenge?”
  • “How did your team work together to solve the problem? What challenges did your team have in working together?”

 

Cross-curricular Connections

Literacy

  • Ask questions (e.g. “Why do we need to sort seeds? How can technology help us do these tasks?”)
  • Communicate thoughts, feelings and ideas. For example:
    • brainstorm unique ways to use materials to sort the seeds 
    • propose improvements to the initial seed sorter design
    • present results of the Design & Build process
    • discuss other seed-related technologies that are involved in farming and agriculture
  • Use a variety of forms (e.g., oral, written, graphic, multimedia) to communicate with different audiences and for a variety of purposes (e.g., to make a prototype model of a seed sorter)

Mathematical Thinking

  • Measure the diameter of the seeds (in millimetres) in preparation for designing and building the seed sorter
  • Using spatial reasoning and sequencing when designing and constructing the seed sorter

Visual Arts

  • Sketching, representing and modeling the seed sorter prototype

Computational Thinking: Abstraction

  • Use spatial reasoning and sequencing when designing and constructing the seed sorter (e.g., draw a concept design of a seed sorter)
Sample seed sorters created by educators during a Let’s Talk Science professional learning session
Sample seed sorters created by educators during a Let’s Talk Science professional learning session (©2018 Let’s Talk Science).

 

Extending the Learning

If your students are interested in learning more, the following may provoke their curiosity:

  • Conduct another inquiry to compare the germination process in different plant species from the seeds that have been sorted in this Design & Build. Is there any connection between the rate of germination and the size of seeds? (For example, do small seeds germinate faster than large seeds?)
  • Indigenous cultures have legends and traditional agricultural customs that involve growing crops together, as opposed to monoculture (single-species crops). The Three Sisters Legend is based on the practice of growing corn, beans and squash together. The corn supports the growing beans and the leaves of the squash cover the ground around the base of the plants to stop weeds from growing. Have students watch a video of The Three Sisters Legend without telling them which plants each of the girls represents.
  • Participate in Tomatosphere™, operated by Let’s Talk Science, and learn whether tomato seeds germinate differently if they have been to space.
Germinating soybeans
Germinating soybeans (Source: <a href="https://pixabay.com/users/jcesar2015-1295189/?utm_source=link-attribution&utm_medium=referral&utm_campaign=image&utm_content=13…">Julio César García</a> via <a href="https://pixabay.com/photos/plants-soybean-soy-nature-1331667/">Pixabay</a>).
Screen capture from The Three Sisters Legend
Screen capture from <a href="https://www.youtube.com/watch?v=Fx9CDVkN9xU">The Three Sisters Legend</a> (Source: <a href="https://www.youtube.com/watch?v=Fx9CDVkN9xU">Widdifield Courtyard on YouTube</a>).

 

Supporting Media

Cover of The Empty Pot by Demi
Cover of The Empty Pot by Demi (Source: <a href="https://openlibrary.org/books/OL3970809M/The_empty_pot">Open Library</a>).

The Empty Pot
By Demi
When Ping admits that he is the only child in China unable to grow a flower from the seeds distributed by the Emperor, he is rewarded for his honesty.
ISBN 0962929859

The Three Sisters Legend (2015) Widdifield Courtyard -- Animated video (3:06 min.) of the Iroquois legend of The Three Sisters garden. 

Learn More

Design & Build a Seed Saver (Lessons)

Students will work collaboratively to design and build a structure that will protect a seed from the elements.

Seed Dispersal (Lessons)

Students develop and apply the skills of observing, comparing, contrasting, sorting and classifying, to investigate how seeds move from place to place.

Design & Build a Travelling Seed (Lessons)

Students will work collaboratively to design and build models of seeds that can travel as far as possible.

Tomatosphere™ (Website)

How does outer space affect plants and seeds? Join Tomatosphere™, a free program where Kindergarten to Grade 12 students use "space" tomato seeds to learn about plants in space, right here on Earth. Tomatosphere™ engages students in real scientific processes that teach and reinforce inquiry skills while they explore concepts related to plants, space, careers, nutrition and agriculture.

Related Topics

Plant Parts
Plant Life Cycles
Testing Designs