3 - 5
Students design a green bean planter and explore planting specifications for green bean seeds. Grades 3-5
Activity 1: The Planter Challenge
- The Planter Challenge handout, 1 per student
- Green bean seeds, 1 packet per group
- Materials that can be used to create a simple machine (Ideas include: duct tape, clear tape, straws, toilet paper tubes, small and large cups, corrugated cardboard, plastic wrap, tin foil, newspaper, scissors, single-hole punch, paper clips, rubber bands, washers, wooden skewers, brass fasteners, string, card stock)
Activity 2: The Math Challenge
- The Math Challenge handout, 1 per student
Essential Files (maps, charts, pictures, or documents)
efficient: achieving maximum productivity with minimum wasted effort or expense
machine: an apparatus using or applying mechanical power and having several parts, each with a definite function and together performing a particular task; a device used to help make work easier
planter: an implement or machine for planting seeds in the ground
Did You Know? (Ag Facts)
- Snap beans were named for the snapping sound produced when breaking off the end of the pod.
- The pod color of snap beans can be green, golden, purple/red, or streaked, but the beans inside are always green.
- Snap beans are nitrogen fixers, which means they draw nitrogen from the air and return it to the soil. Farmers often plant beans to replenish the soil.
- The Asian Yarlong variety of snap beans have pods that measure up to 18 inches long.
- The Spaniards initially used snap beans as ornamental plants because they found the bean pods tough, but liked the flowers.
- Snap beans are the third most commonly grown home garden plant in the United States, outranked only by tomatoes and peppers.
Background Agricultural Connections
This lesson plan is part of a three-lesson series for grades 3-5 designed to teach students about producing, preparing, and preserving agricultural commodities, while fostering an appreciation for how fruits and vegetables "start" in the field and "finish" at the table. Lessons include inquiry-based, real life challenges that engage students in a meaningful way, as they discover the story behind how their food is produced. Lessons in this series include:
Green beans, also called snap beans, are edible pod beans that can be grown as bush beans or pole (climbing) beans. The seeds are planted mechanically by a tractor pulling a machine called a planter. Planters place each green bean seed an optimal distance apart to yield the most beans per acre. The planter looks complex, yet the basic concept is a simple machine that makes production of green beans more efficient and easier for the farmer. The beans are planted at 80 pounds per acre, two lines (rows) per 38-inch bed at six to eight seeds per foot. There are approximately 2,000 seeds per pound, depending on seed size.
In this lesson, students will design a simple green bean planter. They will complete the design process by defining the problem, developing possible solutions, and improving their design. By the end of the lesson, students will appreciate how simple machines make life easier.
Interest Approach - Engagement
- Use the information from the Green (Snap) Beans Commodity Fact Sheet to introduce students to how green beans are produced, the history of green beans, green bean varieties, and their nutritional value. If possible, provide students with a fresh green bean to sample.
- Watch the Green Bean Harvest video until minute 2:12.
- Discuss what is happening in the video.
- Ask the students, "How can machines help farmers?" Point out that machines can help farmers complete their work more efficiently. Machines can be used throughout the entire production process, including planting and harvesting.
Activity 1: The Planter Challenge
- Introduce the challenge. Tell the students they will be building a green bean planter that will mechanically drop three or more seeds onto a piece of masking tape.
- Engage the students by reviewing the six types of simple machines. Write the names of each simple machine on the board, and invite students to give examples for each. If possible, also show an example of each simple machine.
- Show the students the materials and ask, "How can you make a simple green bean planter from these materials?" Give the students additional design parameters and performance parameters:
- The seeds must be dropped by the machine.
- The seeds must be dropped in intervals.
- At least one simple machine must be employed.
- You may only use the materials provided to the class.
- After discussing their ideas, distribute The Planter Challenge handout and instruct the students to complete the Brainstorm and Design section.
- Have the students explain their initial planter design to groups of three to four students. After each individual idea is explained, have the students create a group prototype which could include selecting one design to move forward with, or combining pieces from multiple student designs and creating a new prototype. Have the students draw their proposed group design on The Planter Challenge handout.
- Allow students 20 minutes to build and test their prototype. Remind the students to follow their group prototype design, testing periodically and redesigning as necessary. Design problems and solutions must be noted on The Planter Challenge handout in the Build, Test, Evaluate, and Redesign section. If needed, adjust time and material constraints to meet the needs of the students.
- Evaluate student designs by having groups demonstrate their planter prototypes and determine if they meet design parameters and performance expectations.
- Invite the students to share their designs and how they solved any problems that came up. Emphasize the key themes in this challenge—using simple machines and achieving precise results—by asking questions such as:
- What limited your design solutions?
- What methods did you use to move the seed precisely onto the target row?
- What strategies were successful for planting one seed at a time?
- How did your understanding of simple machines influence the design of your planter?
- Instruct the students to complete the Reflection section of The Planter Challenge handout. Assess student work for completeness and accuracy.
Activity 2: The Math Challenge
- Explain to the students that having access to a machine that plants green bean seeds is important to farmers. Additionally, there is a great amount of planning that needs to happen before the planter can enter the field.
- Distribute The Math Challenge handout. Read the introduction together, and instruct the students to solve the problems independently.
- Lead a class discussion about why we use machines and how long it would take students if they had to plant the seeds by hand. Have the students synthesize the information and share the importance of using machines in agricultural production.
Take the lesson outside and have the students test their planter prototypes in a garden bed. Cover the seeds with soil and apply water. Routinely care for the plants and enjoy a harvest of green beans.
Concept Elaboration and Evaluation
After conducting these activities, review and summarize the following key concepts:
- Machines make the production of green beans and other crops more efficient.
- Planning is necessary before planting a field.
- Farmers use a significant amount of math in their daily operations.
YouTube hosts a variety of videos that show commercial green bean planters in action. Share one of these videos with the class, then create a Venn diagram to illustrate the similarities and differences between student designs and commercially adopted designs.
Gather different types of green bean seeds and classify them according to size, coating, and color, etc.
Explain to the students that engineers must be mindful of design costs. Have the students determine the cost of their prototype.
Find additional activities in the From Start-to-Finish: Producing, Preparing, & Preserving student workbook.
- Contributing Writers and Editors: Liz Baskins, Judy Culbertson, Mindy DeRohan, Len Fingerman, Hayley Lawson, Brenda Metzger, Judee Sani, Sue Squires
- Funding for this lesson series was made possible by the USDA Agricultural Marketing Service through grant 17-0275-022-SC. Its contents are solely the responsibility of the authors and do not necessarily represent the official views of the USDA.
Suggested Companion Resources
California Foundation for Agriculture in the Classroom