Primary Science


Light & Shadows (Important Concept to Remember for PSLE)

Hey there, curious minds!

Ever wondered how shadows play games with light? It’s like a magic show, and we’re here to spill the secrets in a way that’s as easy as 1-2-3!

Watch this video of an artist making shadows dance on a screen.

Did you catch how the artist created a larger and smaller shadow on the screen in the first few seconds?

Important Concept to Remember about Light & Shadows

When his hand is closer to the light source, the bigger the shadow gets!

The further his hand is from the light source, the smaller the shadow gets.


Use these acronyms to remember this concept easily :

NLB (national library board) → Near Light Bigger (shadow)

NSS (national sports stadium) → Near Screen Smaller (shadow)

Another concept we need to understand is that when light is shining from above, the position of the light source changes the length of shadow as well.

The Tale Of Light & Shadows: How Sundials was Used to Tell Time

Now, let’s travel back in time.

In the past, people used sundials to tell time depending on the position of the sun.



The sun rises in the East and sets in the West.

We see the sunrise and sunset because of Earth’s rotation about its own axis. Earth is rotating about its own axis from West to East. So when seen from the Earth, the Sun appears to rise in the East and set in the West.

At 12pm noon, the sun is directly above the sundial/ object. So the shadow will be the shortest.

Use this acronym to remember this concept: NLS- Near Lamp Shorter

Let’s apply the concept on Light & Shadows on this 2019 Science Paper

Let’s practice this question together:



Apply NLB → Near light bigger.

As the shadow of B is the largest, followed by C then A, this tells us that person B is closest to the light source, followed by C, and then A.

The correct answer is option (1).

However, if all three people were at the same distance away from the light source, the shadow of B would be the shortest.

Come Join Us for Trial Class Today!


In the fascinating world of light and shadows, our classroom is a playground of discovery. Using our 3E Framework (Explore, Explain, Expand), we turn learning into an adventure where curiosity leads the way.

Ready to join the excitement? Embark on a journey with us through a trial class, where young minds delve into the magic of science. For inquiries and enrollment, simply reach out at 9616 0312. Let the exploration unfold!

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