Lesson plan Grade 3 Science
Foxhollow's Flooded Playground: A Grade 3 Rain Garden Design Lesson
A grade 3 lesson where students compare test data for two flood-reducing playground designs, a rain garden and packed bare dirt, and make an evidence-based claim.
Objectives
- Students will compare test data from two playground design options to determine which reduces standing water more effectively.
- Students will make a claim about the merit of a design solution, using evidence from a data table.
- Students will explain why plants and soil in a rain garden soak up more rainwater than hard-packed bare dirt.
Vocabulary
- Rain garden
- A rain garden is a shallow planted dip in the ground that catches rain running off a roof or driveway and lets it soak slowly into the soil. Its deep-rooted plants help clean the water.
- Stormwater
- Stormwater is rain or melted snow that flows off roofs, streets, and parking lots. In most towns it goes into storm drains and flows to a stream without being treated, carrying whatever it picked up.
Also: absorb, design solution, evidence
Teacher overview
At the fictional Foxhollow Elementary, the blacktop playground fills with ankle-deep water after every big storm because rain cannot soak into pavement the way it soaks into soil. This lesson gives students test data from two possible fixes the school is considering: a rain garden bed planted with soil and plants, and a patch of hard-packed bare dirt with no plants, and asks them to judge which one is the better solution using that evidence. A common misconception in this lesson is that all ground soaks up water equally well; hard-packed bare dirt has few open spaces, while plant roots and the small organisms in healthy soil keep the soil loose and open extra pathways for water.
Procedure
Hook (5 min): Show a drawing or photo of a flooded blacktop playground after rain and ask: "Why doesn't rain soak into a blacktop the way it soaks into dirt or grass?" Take a few answers without judging which is correct.
Direct instruction (10 min): Explain Foxhollow's problem and introduce two possible fixes: Design A, a rain garden bed of soil and plants, and Design B, a patch of hard-packed bare dirt with no plants. Explain that plant roots, along with the worms and tiny living things in healthy soil, create channels that let water soak into the ground faster than it can soak into hard-packed dirt. Present the class's test data table, where both designs received the same 8 cups of water and were checked 10 minutes later:
| Design | Water poured (cups) | Water still standing after 10 min (cups) |
|---|---|---|
| A: Rain garden (soil + plants) | 8 | 1 |
| B: Packed bare dirt (no plants) | 8 | 4 |
Guided practice (15 min): In pairs, students calculate how many cups of water soaked into each design by subtracting the standing water from the 8 cups poured. As a class, compare the two results and discuss which design absorbed more water and by how much.
Independent practice (10 min): Each student answers three questions on the handout: (1) how many cups of water soaked into Design A, showing the subtraction; (2) how many cups soaked into Design B; (3) which design reduces the flooding hazard more, and by how many cups, written as a one-sentence claim supported by the data.
Closure / exit ticket (5 min): On an index card, students answer: "If the school builds a full-size version of Design A along the whole playground edge, name one plant-related reason it might soak up even more water than our small 8-cup test bed." Collect the cards before dismissal.
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: 7 cups. 8 − 1 = 7.
- Answer: 4 cups. 8 − 4 = 4.
- Answer: Design A, the rain garden, reduces the flooding hazard more, by 3 cups (7 − 4 = 3). An example claim: "Design A reduces flooding better because it soaked up 7 of the 8 cups poured, while Design B only soaked up 4."
- Exit ticket answer: Accept any reasonable plant-related reason, such as: a full-size rain garden would have many more roots spreading through more soil, opening more paths for water to soak down, and the plants themselves would take up some of the water too.
Differentiation
Support (below grade level)
Provide the subtraction for Design A already worked out (8 − 1 = 7 cups) as a model, so students only need to complete Design B's subtraction using the same method. Give a sentence frame for the claim: "Design ___ works better because it soaked up ___ cups, more than Design ___'s ___ cups."
Extension (above grade level)
Ask students to predict, using the same pattern from the 8-cup test, what would likely happen if the school tested both designs again with 12 cups of water during a bigger storm. Have them explain their reasoning in writing without being given new numbers, based only on how each design performed in the original test.
ELL supports
Pre-teach "absorb," "soak in," "claim," and "evidence" using a simple sponge demonstration: pour water on a dry sponge and a dry rock side by side so students see the difference before reading the data table. Provide picture cards showing Design A (plants and soil) and Design B (packed bare dirt) to support the vocabulary.
Extensions
Invite students to notice, after the next real rainstorm, whether puddles at their own school form on pavement or on grass and soil, and to bring back one observation to share with the class, connecting the lesson's data to something they can see for themselves.