Science lesson plan · 3rd grade (Year 4 in England) · 30 minutes
Planning a fair test
Working scientifically
CCSS NGSS.SEP 3CCSS NGSS.3-PS2-1England: KS2 Y3–Y4 Working scientifically
Objective and success criteria
Students will: Planning a fair test.
- I can answer questions on today's skill on my own, without help.
- I can explain each step and say why it works.
- I can check my answer and spot a mistake.
Before and after
Needs first: Choosing a measuring tool
Leads to: Independent, dependent and control variables
Materials: Simple equipment for a fair test, Results table template, Mini whiteboards, A diagram or short video clip of the idea, Printed student sheet (below).
Warm-up · 4 min
- Quick retrieval from earlier learning (Choosing a measuring tool). Students answer on mini whiteboards.
- Show answers together and note who needs support in the main task.
- Which tool would you use to measure the mass of a pumpkin? (a ruler or tape measure / a thermometer / weighing scales / a stopwatch or timer) → weighing scalesPrompt: Is it a length, a temperature, a mass, a time or an amount of liquid?
- What could you measure with a ruler or tape measure? (how tall a sunflower has grown / the temperature outside / how much milk is in a glass / how heavy an apple is) → how tall a sunflower has grownPrompt: What does this tool measure: length, temperature, mass, time or volume?
- Zara wants to know if her bean plant grows taller each day. What should she use? (a thermometer / weighing scales / a stopwatch / a ruler) → a rulerPrompt: She wants to know how tall it is.
Hook · 3 min
- Show a simple experiment with one thing changed and ask what makes it a fair test.
- Share the objective: Planning a fair test. Read the success criteria together.
I do: model it · 7 min
- Work through the example out loud, saying why you do each step, not just what you do.
- Example: Leo tests which paper towel soaks up the most water. What should he change?
- Step 1: He is testing types of paper towel, so that is the only thing he changes.
- Step 2: So the answer is: the type of paper towel
- Answer: the type of paper towel
- Pause after each step and ask a student to say what comes next.
We do: guided practice · 6 min
- Do these together. Students try each step on whiteboards before you reveal it.
- Use the hints as prompts rather than giving the answer.
- Isla tests which ball bounces highest. She drops one ball from 1 m and another from 2 m. What is wrong? (The drop height should be the same / Nothing, it is fair / She should use only one ball / She should not measure the bounce) → The drop height should be the samePrompt: What is she trying to compare?
- Which question can be answered with a fair test? (Who is the best scientist? / Does a heavier parachute fall faster? / What is your favourite plant? / Is a rainbow beautiful?) → Does a heavier parachute fall faster?Prompt: A fair test changes one thing and measures another.
You do: independent practice · 7 min
- Students work on the student sheet. Circulate and check the first two answers of every student early.
- Students who finish: write a question of their own for a partner, with the answer.
The 6 questions are on the student sheet below, with answers in the key.
Exit ticket · 3 min
- Two questions on their own. Sort answers into got it / nearly / not yet to plan the next lesson.
- Priya tests which surface a toy car rolls furthest on. What must she keep the same? (how far the car rolls / nothing / the height of the ramp / the type of surface) → the height of the rampPrompt: Only the surface should change.
- Which question can be answered with a fair test? (Does a heavier parachute fall faster? / Who is the best scientist? / Is a rainbow beautiful? / What is your favourite plant?) → Does a heavier parachute fall faster?Prompt: A fair test changes one thing and measures another.
Watch out for
- Everyday meanings of words getting in the way of the science meaning: define key words explicitly.
- Remembering facts without the reason: ask "why?" and "what is the evidence?"
Support and stretch
Support
- Review first: Choosing a measuring tool.
- Use concrete materials: simple equipment for a fair test.
- Give the first step of each question, or a partly worked example to finish.
- Pair with a confident partner for the guided practice.
Stretch
- Move on to: Independent, dependent and control variables.
- Explain a common mistake in writing and how to fix it.
- Write a word problem that uses today's skill, then solve a partner's.
Homework and more practice
Free online practice with hints and printable worksheets for this skill: eurekami.com/science/grade-3.
Free lesson plan from eurekami.com/lesson-plan-builder