Stretching and Squashing

Lesson Overview

Year Group: Year 2
Subject: Science
Duration: 90 minutes
Class Size: 29 students
NC Programme of Study:

• Key Stage 1 Science – Working Scientifically & Everyday Materials
• Focus: Describing how materials can be changed by stretching, squashing, bending, and twisting.
• Big Question: If I can stretch it, can I squash it?

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Lesson Objectives

By the end of the lesson, students will be able to:

• Identify materials that can be stretched or squashed.
• Describe how the shape of some materials changes when forces are applied.
• Make predictions about materials and test their properties.
• Work scientifically through observation, discussion, and simple testing.

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Resources Needed

Per Pair of Students:

• Small rubber bands
• Ball of blu-tack/playdough
• Sponge
• Plasticine
• Metal spoon
• Cotton wool
• Balloon
• Paper clips
• Worksheet for recording predictions and observations

For Teacher:

• Large elastic band for demonstration
• Soft and rigid plastic bottle
• Chart paper & markers
• Whiteboard & pens

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Lesson Structure

1. Introduction and Hook (15 mins) 🔥

Engage Through Prediction

1. Question the Class:

   • Hold up a rubber band and stretch it. Ask: "What is happening to it?"
   • Then squash a ball of blu-tack. Ask: "What is happening now?"
   • Introduce the Big Question: If I can stretch it, can I squash it?

2. Concept Introduction:

   • Explain that some materials can change shape when we squash them, stretch them, or squeeze them—and some don’t change back!
   • Show a rigid plastic bottle and squeeze it. Point out: some things can change permanently!

3. Class Brainstorm:

   • Ask: "What materials do we think can be stretched? What about squashed?"
   • Record predictions on the board under “Stretch” and “Squash” columns.

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2. Hands-On Investigation (40 mins) 🔬

Step 1: Predict (5 minutes)

• In pairs, students receive a worksheet with pictures of materials.
• They predict whether each material can be stretched, squashed, or both.

Step 2: Investigate (25 minutes)

• Each pair of students receives different materials. They must test whether they can be stretched, squashed, or both.
• Students write or draw their observations. What happens when they let go? Does the material return to its original shape?

Step 3: Discuss Findings (10 minutes)

• As a class, fill in a large table on the board.
  • Which objects stretched?
  • Which could be squashed?
  • Did any material NOT change at all?
• Discuss surprising results!

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3. Explanation and Reflection (20 mins) 🧠

Class Discussion (10 minutes)

• Key Question: Can materials do both?
  • Some materials only stretch, but others can be stretched AND squashed, like playdough.
• Introduce the idea of elastic and malleable materials.
  • Elastic: Can stretch AND return to its shape (rubber band).
  • Malleable: Can be squashed or shaped (plasticine).
• Ask: Why are these properties useful? (E.g. rubber in balloons, soft materials in cushions).

Mini Experiment – Balloon Question (10 minutes)

• Inflate a balloon slightly. Ask: "Can I squash it?" (Yes!)
• Stretch the uninflated balloon. Ask: "Can I stretch it?" (Yes!)
• Fully inflate the balloon. Ask again: "Can I squash or stretch it anymore?"
• Discuss: Some materials change their behaviour when other forces, like air, are added!

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4. Plenary (15 mins) 🎯

Quick Quiz – True or False (5 minutes)

• "A metal spoon can be stretched easily." (False)
• "Playdough can change shape when squashed." (True)
• "A rubber band is very stiff." (False)

Exit Question (5 minutes)

• Show two new objects (e.g. a pencil and a towel). Ask: Do you think we can stretch or squash these? Why?

Final Thought (5 minutes)

• Ask students if they use stretchy or squashy materials in their day-to-day life.
• Challenge for home: Find one object at home that can be stretched and one that can be squashed!

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Assessment Opportunities

• Discussion Participation: Are pupils able to explain their ideas?
• Worksheets & Predictions: Did pupils correctly identify which materials could be stretched or squashed?
• Reflection Questions: Can pupils describe why different materials behave in certain ways?

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Adaptations for Different Needs

Student Need	Adaptation
Support with writing	Allow students to draw results instead of writing.
More Challenge	Ask pupils to think of other forces that might change a material. Could freezing or heating affect materials?
Visual Learners	Use real-life examples and large visual charts
Kinesthetic Learners	Hands-on investigation to explore materials.

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Teacher Reflection

• What went well?
• Did students apply their learning to real-world examples?
• Were misconceptions addressed?
• How could this lesson be improved for next time?