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How does a pencil sharpener work? |
Stay sharp! Pencils can only write for so long before their graphite tips are worn down to nubs, and then we can’t write anymore! This is when we go to the very helpful machines called “pencil sharpeners.”
All pencil sharpeners work pretty much the same way. A pencil is placed inside a hole in the sharpener where there is a sharp metal blade tilted at a special angle. This angle will give the pencil its pointy shape. The blade is actually able to shave off the wood and graphite of the pencil until the pencil is ready to write!
In some small box pencil sharpeners, you use your hand to turn the pencil against the blade. In wall-mounted and desk-mounted pencil sharpeners, we hold the pencil still and turn a crank that spins the blade around the pencil. In electric pencil sharpeners, we just hold the pencil still while a motor spins the blade around the pencil for us.
Once your pencils are pointy and ready to write, remember to be careful because they are very sharp!
The Number 2 Pencil
You might notice that some pencils have numbers on them. Most often you’ll see the number 2 on a pencil that you use to write and draw. When you get older and take tests where you fill in bubbles to mark your answers, you’ll be asked to use a number 2 pencil. What’s so great about the number 2?
The numbers actually tell us how hard the core of the pencil is. The core is the dark gray part that actually does the writing. It’s made of graphite, a soft metal, but it can also be mixed with clay to make it harder and sturdier.
A number one pencil is mostly graphite, but is very soft. Because it’s mostly graphite, it makes a very dark mark. Number 2 pencils are slightly less dark, but a little more sturdy. They have more clay in them than number 1 pencils. Most fill-in-the-bubble tests use computer scanners that can read the special marks left by number 2 pencils. Your test will actually be graded by a computer!
Numbers 3 and 4 pencils are even sturdier than Number 2 pencils, but they leave lighter marks on paper. Thanks to their sturdiness, they won't break very easily. You might not need to use a pencil sharpener as much!
Next time you’re drawing or writing, check out what’s written on your pencil. Do you see any numbers?