Lesson plan Grade 4 English Language Arts
Four Stages at Millbrook: A Grade 4 Short Research Writing Lesson
A grade 4 lesson where small groups research one stage of a fictional water treatment plant, then write grouped informative paragraphs that combine into a class sequence.
Objectives
- Students will research one assigned stage of a water treatment plant using a provided info card.
- Students will write an informative paragraph about their stage that groups what happens separately from why it matters.
- Students will sequence all four stages correctly as a class using evidence from every group's paragraph.
Vocabulary
Key words: treatment plant, mixing, filtering, disinfecting, sequence
Teacher overview
Millbrook Water Treatment Plant, a fictional plant used for this lesson, cleans river water in four stages before it reaches the fictional town's faucets: mixing, filtering, disinfecting, and storage. Rather than reading one long passage about all four stages at once, students work in four small groups, each researching a single stage from a short info card, then write an informative paragraph that groups what happens at that stage separately from why the stage matters. The lesson closes by assembling every group's paragraph into a class-wide sequence, so students experience firsthand how splitting one big topic into its parts, and then researching each part, builds a complete picture. A common misconception this lesson addresses is that "cleaning water" is a single step; the four info cards make clear it is a sequence of distinct jobs, each solving a different problem.
Procedure
Hook (5 min): Ask students to imagine filling a glass with water straight from a muddy river and describe what they would want done to that water before drinking it. List their ideas on the board (take out the mud, kill germs, and so on) without naming the real stages yet.
Group assignment and reading (10 min): Divide the class into four groups. Give each group one info card from the Student Handout: Mixing (chemicals clump tiny dirt particles together so they are easier to remove), Filtering (water passes through layers of sand and gravel that catch the clumped dirt), Disinfecting (a small amount of chlorine kills remaining germs), or Storage (clean water waits in a covered tank until it is needed). Groups read their card twice and underline the sentence that explains why their stage matters.
Guided planning (8 min): Model, using the Mixing card as a whole-class example, how to split one card into two paragraph parts: "What happens" (chemicals are added and the water is stirred) and "Why it matters" (clumped dirt is far easier to filter out than dirt spread through the whole tank). Groups then plan their own two-part paragraph on chart paper using the same structure.
Independent group writing (15 min): Each group writes its informative paragraph on chart paper, with a clear "What happens" part and a clear "Why it matters" part, using their info card as source material. Every group member contributes at least one sentence.
Sequencing and gallery walk (12 min): Groups post their chart paper around the room. The class walks the gallery in silence, reading all four paragraphs, then returns to seats to place the four stages in the correct order on a sequencing strip (a printed template with four blank boxes) using evidence from the paragraphs rather than guessing.
Closure / formative check (5 min): Ask the class: "Which stage would you have to run first, filtering or mixing, and how do you know from what you read?" Cold-call one student to answer and confirm the correct order (mixing, filtering, disinfecting, storage) before dismissal.
Student Handout
Stage info cards. Print the four cards, cut them apart, and give one card to each group.
Mixing card. River water carries tiny bits of dirt that are too small to see one at a time. At the mixing stage, workers add chemicals to the water, and large paddles stir it slowly. The chemicals make the tiny bits of dirt stick together into bigger clumps. This stage matters because clumped dirt is far easier to filter out than dirt spread through the whole tank.
Filtering card. At the filtering stage, the water moves slowly down through deep layers of sand and gravel. The sand and gravel catch the clumped dirt, and the water that comes out at the bottom is clear. This stage matters because it takes out the dirt that makes water cloudy, and it catches some germs along with the dirt.
Disinfecting card. Even clear water can still hold a few germs that are too small to see, and some germs can make people sick. At the disinfecting stage, workers add a small, carefully measured amount of chlorine. The chlorine kills the remaining germs, and a little of it stays in the water on the way to homes. This stage matters because water that looks clean is not always safe to drink.
Storage card. At the storage stage, clean water waits in a covered tank until it is needed. The cover keeps out rain, dust, leaves, and animals. People in town use the most water in the morning and the evening. This stage matters because the tank keeps clean water ready at those busy times, even when many people turn on their taps at once.
Sequencing strip. Write one stage name in each box, in the order the water moves through the plant. Under each box, copy one detail from the paragraphs that shows why the stage belongs in that place.
| Box 1 | Box 2 | Box 3 | Box 4 |
|---|---|---|---|
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 (sequencing strip): The correct sequence is mixing, filtering, disinfecting, storage. Each stage's info card names what problem it solves, and the storage card explicitly states that clean water waits there "until it is needed," showing it comes last.
- Answer (closure question): Mixing comes first. The mixing stage clumps dirt together so the filtering stage, which comes next, can catch it, and the dirt is only clumped after the mixing stage has already happened.
Differentiation
Support
Provide sentence starters for both paragraph parts ("At this stage, the water ___." and "This stage matters because ___.") and reduce each info card to two short bullet points rather than full sentences for groups that need a lower reading load.
Extension
Ask early-finishing groups to add a third paragraph part explaining what might happen to the town's water if their assigned stage were skipped entirely, using only reasoning from their info card and the other groups' paragraphs.
ELL supports
Pair the vocabulary word on each info card (mixing, filtering, disinfecting, storage) with a simple icon (swirling arrows, a screen, a droplet with a plus sign, a covered tank) printed directly on the card. Allow group paragraphs to be dictated to a scribe or built from the sentence starters listed under Support.