Education Through Entertainment

How to Perform Pencil Poke Trick | Fun Science Experiment

Posted on Thu, Aug 11, 2016

Here's a fun trick (that's actually a science experiment) that you can do at home.  Learn how you can run a sharpened pencil all the way through a plastic bag filled with water without spilling a drop.  All you need are some sharpened pencils, a plastic bag filled with water, and our secret technique!

Watch the video and follow the directions below to learn how to perform this impressive stunt yourself!

Watch this video to see how to perform the "Pencil Poke Trick":

Step 1: What You'll Need

You need just a few things to perform this trick:

  • Pencils (1-6)

  • Pencil sharpener
  • Plastic sandwich bag

  • Water

Step 2: Prepare the Plastic Bag and Pencils

Did you find everything you need?  Okay, great!  Let's get started.

First, sharpen all of your pencils.  They need to be as sharp as you can make them, so give them all a good once over to make sure.

Then, fill your plastic bag with ordinary tap water until it's mostly full.  Don't fill it too much or you won't be able to close it; leave just a bit of space at the top.


Step 3: The First Pencil

Okay, are you ready?  You sure?  Take a deep breath - let's try this!

Hold one of your sharpened pencils against the surface of the bag.  Gently rotate the pencil while applying light pressure, slightly increasing the pressure as you push.

Press your sharpened pencil against the plastic bag

Keep pushing until the pencil goes through the first layer of plastic!  Now, keep pushing until the pencil goes through the water and is pressed against the other wall of the plastic bag.  Again, keep up the pressure and push the pencil through the other piece of plastic.  Whatever you do, don't pull the pencil out!  Keep moving forward and twisting the pencil lightly as you go.

The pencil goes straight through the bag!

What's happened here is the pressure of the water inside the bag has caused the plastic to form a seal around the pencil.  As long as the pencil is in there blocking the hole, no water will leak out!  

Step 4: Add More Pencils!

Don't stop there - try a second pencil!

Try this one at a different angle than the original, but use the same technique.

Try a second pencil!

Once you get a second pencil in place, try for a third!

Try even more!

You can add as many pencils as you have sharpened!

The Pencil Poke Trick is something you'll want to show your friends and family, and it's so easy to do, you can teach them how it works, too!  You can also try other objects instead of pencils, such as sharp wooden skewers.  It helps some objects to have a bit of dish soap smeared on the surface in order to create a stronger seal.

Try it at home!

Check back again for even more do-it-yourself science experiments from Mobile Ed's Building Up STEAM series!  

If you like DIY experiments like these, you should see the kinds of spectacular demonstrations we bring to schools with our live school assembly presentations.  Take a look at The Magic of Science, Physics is Fun, Forces and Motion and Crime Scene Science, each full of interactive demonstrations that kids love.

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About Mobile Ed Productions:

Mobile Ed Productions, Inc. has been in business since 1979, producing educational, entertaining school assemblies and hands-on workshops.  Based out of Michigan, the company creates, designs, markets and distributes innovative ways to make learning fun in the form of live presentations and interactive exhibits.

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Topics: science fair projects, science enrichment, Teaching Science, Hands On Science, making science exciting, DIY, Building Up STEAM, science experiments