Lesson plan Grade 3 English Language Arts
How Thistlewood's Water Gets Clean: A Grade 3 Writing Lesson
A grade 3 informative writing lesson in which students learn the three steps of a fictional town's water treatment plant and write a grouped-facts paragraph.
Objectives
- Students will identify the three basic steps a water treatment plant uses to clean water.
- Students will write an informative paragraph with a topic sentence, grouped facts, and a closing sentence.
Vocabulary
Key words: treatment plant, filter, disinfect, topic sentence
Teacher overview
The town of Thistlewood (a fictional town used for this lesson) draws its drinking water from a nearby river, which means the water must be cleaned before it reaches any tap. This lesson uses Thistlewood's water treatment plant as the shared topic for an informative paragraph: one main idea, that the plant cleans the water, supported by three grouped facts, settling, filtering, and disinfecting. Because informative writing depends on grouping related facts under one topic sentence, the treatment process gives students three naturally ordered steps to group. Naming a concrete three-step process gives the class a shared set of facts to organize, rather than a vague topic like "water is important."
Procedure
Hook (5 min): Show a glass of muddy river water next to a glass of clear tap water. The glasses are for looking only, and no one drinks from either one. Ask: "What has to happen to the muddy water before anyone could drink it safely?" Collect ideas on the board.
Direct instruction (15 min): Introduce Thistlewood's water treatment plant and its three basic steps, drawn on chart paper as a simple flow line: Settle (heavy dirt sinks to the bottom of a big tank), Filter (the water passes through layers of sand and gravel that catch smaller bits of dirt), and Disinfect (a carefully measured, safe amount of a cleaning chemical kills germs that could make people sick). Model turning these three steps into an informative paragraph: write a topic sentence ("Thistlewood's water treatment plant uses three steps to make river water safe to drink."), one sentence per step, and a closing sentence.
Guided practice (10 min): As a class, revise the modeled paragraph together by suggesting a stronger closing sentence, and identify which sentence in the model paragraph is the topic sentence and which three sentences are the grouped facts.
Independent writing (10 min): Using a paragraph frame handout, students write their own informative paragraph about Thistlewood's treatment plant, including a topic sentence, three grouped facts (settle, filter, disinfect), and a closing sentence.
Closure / exit ticket (5 min): Students answer aloud or on an index card: "Which step comes first: settling, filtering, or disinfecting?"
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: Settling comes first. Heavy dirt has to sink to the bottom of the tank before the water moves on to be filtered and disinfected.
Differentiation
Support
Provide the paragraph frame with the topic sentence and closing sentence already written, so students only need to write the three grouped-fact sentences in the middle.
Extension
Ask students to add a fourth sentence explaining why the settle step has to happen before the filter step, using the word "because."
ELL supports
Pre-teach "settle," "filter," and "disinfect" with a simple three-picture sequence (a jar with dirt sinking, water passing through sand, a drop of chemical) posted next to the vocabulary words. Allow students to complete the paragraph frame with phrases before turning them into full sentences.
Extensions
Ask students to interview a family member about where their own home's water comes from, then compare that answer with Thistlewood's river source during a short class discussion the following day. Classes that finish early could also design a simple three-panel poster illustrating the settle, filter, and disinfect steps, using their informative paragraph as the poster's caption, which turns the writing task into a piece of public-facing explanation similar to the signs some real treatment plants post for visitors.