OUR WONDROUS WORLD | CLASS 4 EVS
HOW THINGS WORK
15 Important Terms and Their Meanings
Learn • Observe • Explore • Discover
Welcome, Young Scientists!
Do you know how things spin, float and sink? Let's learn some interesting words from our chapter. Read the explanations, look at the pictures and test your knowledge!
15 Important Terms to Learn
Spinning
When an object turns round and round around a point, it is called spinning.
Example: A coin and a ceiling fan spin.
Spinner
An object that spins when we give it a push or turn.
Example: A toy top (lattu) is a spinner.
Centre
The middle point of an object is called its centre.
Example: The middle point of a circular spinner.
Balance
Balance means keeping an object steady without falling to one side.
Example: A spinner with a toothpick at its centre can spin upright.
Charkha
A spinning wheel used to twist cotton fibres into thread.
Example: Mahatma Gandhi used a charkha to make handmade clothes.
Floating
When an object stays on the surface of water, it is called floating.
Example: A leaf floats on water.
Sinking
When an object goes down to the bottom of water, it is called sinking.
Example: An iron nail sinks in water.
Prediction
A prediction is a guess about what may happen before doing an activity.
Example: Guessing that a leaf will float before putting it in water.
Observation
Observation means carefully watching and noticing what happens during an activity.
Example: Watching whether a stone floats or sinks.
Material
The substance from which an object is made is called its material.
Example: A bottle may be made of plastic and a spoon of steel.
Shape
The outer form or appearance of an object is called its shape.
Example: A ball is round and a box may be square.
Aluminium Foil
A thin, shiny sheet of aluminium metal.
Example: We can fold aluminium foil into a cup or ball to test floating and sinking.
Strength
Strength means how strong an object is and how well it can resist breaking.
Example: A strong boat does not break easily.
Design
Design means the way something is planned, shaped or made.
Example: Children can design boats using paper, coconut shells or ice-cream sticks.
Wooden Top (Lattu)
A traditional Indian toy made of wood that spins when given a push.
Example: Children play with a lattu by making it spin on the ground.
Quick Revision
Remember these simple meanings:
- Spinning: Turning round and round.
- Spinner: An object that spins.
- Centre: The middle point.
- Balance: Staying steady.
- Charkha: A wheel used to make thread.
- Floating: Staying on water.
- Sinking: Going down in water.
- Prediction: A guess before an activity.
- Observation: Carefully watching.
- Material: What an object is made of.
- Shape: The form of an object.
- Aluminium foil: A thin, shiny metal sheet.
- Strength: Ability to resist breaking.
- Design: Way something is planned or made.
- Wooden top: A traditional spinning toy.
Test Your Knowledge!
Choose the correct answer for each question.