Lesson plan Grade 3 Engineering & Design
Larkspur Farm Water Lift: Designing a Tool to Raise Water
A grade 3 engineering lesson where students design and compare two tools that lift water from a low tub to a higher tub, modeling how a pump moves water uphill.
Objectives
- Students will define a water-lifting problem with a success criterion and part limits.
- Students will design and build two different tools that raise water to a higher tub.
- Students will compare their two designs and choose the one that better meets the criteria.
Vocabulary
- Pump
- A pump is a machine that adds energy to water to move it or push it uphill, doing the job gravity cannot do on its own. Water systems use many different kinds of pumps to move water from wells, through treatment, and out to customers.
Also: lift, design, compare, criteria
Teacher overview
Larkspur Farm keeps its water in a low tub, but the garden beds sit up on a bench where the water needs to go. Real water systems solve this with a pump, a machine that lifts water uphill. In this lesson, groups act as pump designers: they define the lifting problem, build two different tools from the same small kit of parts, and compare which tool moves more water to the higher tub without spilling. Results depend on how carefully each group builds and pours, so groups compare their two tools by how much water arrives in the high tub and how much ends up on the floor, rather than by a measured number.
Procedure
Hook (5 min): Set a full low tub on the floor and an empty tub on a chair or bench. Ask a volunteer to move water from the low tub to the high one using only their hands, and let the class see how much spills. Ask, "What tool could move this water up more easily?" Name the tool a pump.
Define the problem (7 min): Agree on the success criterion with the class: water reaches the high tub with as little spill as possible. List the constraints: each group gets three cups, one length of string, a scoop, cardboard, and tape, and has time to build two tools. Write "two designs" on the board so every group knows to try more than one idea.
Brainstorm and sketch (8 min): Each group sketches two different lifting tools, such as a cup on a string that is pulled up hand over hand, or a scoop taped to a cardboard arm that swings water over the edge. The two sketches must be different so there is something to compare.
Build (15 min): Groups build both tools from the shared parts. Remind them that a cup lifted straight up spills less than one that swings wide, and that tape can seal a scoop so water does not run out the side.
Test and compare (10 min): Lay paper towels under the high tub so spills are easy to see and no one slips. Groups use each tool to move water for the same short count, such as ten pulls or ten swings, and watch which tool gets more water into the high tub with less spill on the floor. Pour the water back into the low tub before testing the second tool. They record which design worked better on the handout.
Debrief (5 min): Groups name their better design and one reason it won. For a formative check, ask each group to finish the sentence, "Our better tool met the criteria because ___," aloud; any group that cannot name evidence gets a quick prompt to point to the spill on the floor.
Student Handout
Fill in the chart and answer the questions about your two water-lifting tools.
| Tool 1 | Tool 2 | |
|---|---|---|
| What it is made of | ||
| Did water reach the high tub? | ||
| How much spilled? (a little / a lot) |
- Which tool met the criteria better, Tool 1 or Tool 2? Tell how you know.
- What is one part of your better tool that you would change to spill even less?
- Real farms and towns use pumps to lift water. Why is a tool better than using bare hands for this job?
From Water for Schools (waterforschools.org). This material is in the public domain (CC0) and may be copied, edited, and shared freely.
Answer Key
- Answer: Accept either tool as long as the choice matches the group's own recorded results, such as "Tool 2, because more water reached the high tub and less spilled on the floor."
- Answer: Accept any sensible design change tied to a real problem the group saw, such as taping the scoop edge, using a shorter string swing, or adding a lip to the cup to stop spills.
- Answer: Accept answers explaining that a tool moves more water at once, spills less, or is easier and faster than cupped hands, which is the same reason towns use pumps instead of carrying water.
Differentiation
Support
Provide these groups one worked design as a starting model, such as a cup already tied to a string, so they can focus on building a second, different tool to compare it against. Offer a picture chart of "a little spill" versus "a lot of spill" to make recording easier.
Extension
Ask these groups to design a third tool that lifts water in fewer moves than either of their first two, and to explain the trade-off between speed and spilling. Have them predict which design a real farm would choose and why.
ELL supports
Pre-teach "pump," "lift," and "spill" with a short demonstration and labeled pictures. Provide sentence frames for the handout, such as "Tool ___ was better because ___." Allow students to draw arrows on a diagram to show how water moves instead of writing full sentences.
Extensions
Show a short clip or picture of a hand pump or an Archimedes screw and ask students to find the part that does the lifting. Groups can look for pumps in their own lives, such as a soap dispenser or a bike pump, and share how each one moves something from low to high.