🛝 How does a seesaw balance?

You jump on one side, your friend on the other — up, down, up, down! But sometimes it gets stuck with one side stuck on the ground.

🧒 🧒

In this Spark you'll discover the secret rule that makes a seesaw sit perfectly level. Ready? Tap “Next” to begin!

🔍 The parts of a seesaw

Every seesaw has 3 important parts. Tap each glowing dot to find out what it does!

1 2 3
Tap dots 1, 2 and 3 to reveal all the parts.

⚖️ When both sides match

If two people weigh the same and sit the same distance from the middle, the seesaw stays perfectly level. Nobody goes up, nobody goes down.

3kg 3kg

👀 Look: same weight + same distance = balanced!

But what happens when one side is heavier? Let's test it next… ➡️

🏋️ Which side goes down?

A big elephant 🐘 and a little mouse 🐭 sit the SAME distance from the middle. Which side will sink to the ground?

🐘 🐭
Tap your answer!

✨ Distance is a superpower

Here's the secret: a lighter person can still win — by sitting further away from the middle!

The heavy 4kg block is close in. Slide the light 2kg block out until the seesaw is perfectly level.

4kg 2kg
Mouse block distance: 1.0 m
Slide it out to make both sides equal.

🧠 The Balance Rule

Scientists found the magic recipe:

weight × distance on each side must be EQUAL.

The left side is fixed at 3kg × 2m = 6. Change the right block's weight and distance to also make 6!

3kg
Right weight: 1 kg
Right distance: 1.0 m
Right side: 1 × 1.0 = 1
Make the right side equal 6 to balance!

🏆 Brain challenge

The puzzle: A heavy big brother 🧑 and a light little sister 🧒 want to seesaw together and stay level. They weigh different amounts.

What is the smartest way to balance them?

Pick the best answer — you can try again!
🎉🛝🎉

You're a balance master!

Here's everything you discovered:

  • ⚖️ A seesaw balances on the fulcrum in the middle.
  • 👬 Same weight + same distance = perfectly level.
  • 🐘 The heavier side sinks down.
  • ✨ A light person can still win by sitting further out!
  • 🧠 The rule: weight × distance must be EQUAL on both sides.
weight × distance = weight × distance

Next time you're at the playground, try it out — slide closer and further and feel the rule for yourself! 🌟

Well done, scientist! 👏