Machines

Grade 3 · General Science

Semester 1 | Period 3 | Week 17

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Subject: General Science

Semester: 1

Period: 3

Week: 17

School Name:
Teacher’s Name:
Subject: General Science
Grade Level: Grade 3
Date: Week 17
Lesson Duration: 45 minutes
Week & Period: Week 17, Period 3
Topic: Machines
Sub-topic: Simple Machines – Types, Examples, and Uses

Learning Objectives
By the end of the lesson, students should be able to:
Learners will name examples of the six simple machines (lever, pulley, wheel and axle, inclined plane, wedge, screw).
Learners will explain the uses of simple machines in making work easier.

Previous Knowledge
Students already know:
Work involves applying force to move objects. Machines can help reduce effort.

Instructional Materials
Models or images of simple machines, objects for demonstrations (lever, pulley, inclined plane, wedge, screw), worksheets.

Lesson Development – ABC Model

A – Anticipation (Warm-up / Starter)
Time: 5–10 minutes
Ask learners to describe how they open doors, lift heavy objects, or carry water. Discuss whether tools help make these tasks easier.

B – Building Knowledge (Main Lesson Body)
Time: 25–30 minutes

Learners’ Activities (Expanded):

  • Learners observe models or images of the six types of simple machines: lever, pulley, wheel and axle, inclined plane, wedge, and screw.
  • Students identify each machine and discuss where they see them in daily life, for example:
    • Lever: seesaw, crowbar, scissors
    • Pulley: flagpole, well bucket, curtain rod
    • Wheel and axle: door knob, bicycle wheels, rolling chair
    • Inclined plane: ramps, slides, wheelchair ramps
    • Wedge: knife, axe, doorstop
    • Screw: jar lids, bolts, spiral staircase
  • Learners discuss how each machine reduces effort or makes work easier, such as changing the direction of force, spreading effort over a distance, or multiplying force.
  • Optional activity: learners create a mini “Simple Machines Gallery” by drawing, labeling, or bringing examples from home or school.

Assessment Checks (Expanded):

  • Ask learners to name all six simple machines.
  • Ask learners to explain how one simple machine helps reduce effort, e.g., how a ramp allows lifting heavy objects with less force than lifting straight up.
  • Observe participation in discussions and hands-on identification to ensure learners understand both names and functions of the machines.

Notes (Expanded & Detailed):

  • The six simple machines are:
    • Lever – a rigid bar that pivots on a point to lift or move loads
    • Pulley – a wheel with a rope or belt that changes the direction of force
    • Wheel and axle – a wheel attached to a rod to make movement easier
    • Inclined plane – a sloping surface that reduces effort needed to lift objects
    • Wedge – a tool that separates objects or holds them in place
    • Screw – an inclined plane wrapped around a cylinder to hold or lift objects
  • Uses: Simple machines make work easier by changing the direction or amount of force applied.
  • Daily examples: seesaws, ramps, knives, jar lids, flagpoles, door knobs, bicycles.
  • Demonstrations and real-life examples enhance understanding and help learners connect concepts to practical experiences.
  • Encourage learners to look for simple machines at home and school and note how they reduce effort or make tasks easier.

C – Consolidation (Conclusion & Assessment)
Time: 5–10 minutes

Summary:
Recap the six types of simple machines and their uses. Reinforce how they help reduce effort in daily activities.

Evaluation Method (Expanded)
Exit slip/quiz: Learners name three simple machines and explain how one of them helps make work easier.
Teacher will collect slips and provide oral feedback.

Assignment (Expanded)
Observe and list simple machines used at home or school and describe how they make work easier.

Follow-up Activity
Create a class display showing models or pictures of simple machines and their uses.

Differentiation / Inclusive Strategies
Provide labeled diagrams for visual learners. Pair learners for hands-on demonstrations. Offer simplified explanations for learners who need extra support.

Teacher’s Reflection (After Class)
What worked well? ___________________________________________
What needs improvement? ____________________________________
Students’ engagement level: ☑ High ☑ Medium ☑ Low