5 Minute STEM Activity 5 - Step Through A Hole In A Postcard

Here's something for the engineers of the future to get their teeth into. You can make a hole in more than one way, and if you do it carefully, you can even walk through a hole in a postcard...

This activity is quite hard because it requires concentration and careful cutting. Younger scientists may need older assistance, and there is always sticky tape!

Step Through A Postcard

EQUIPMENT:
A postcard sized piece of thin cardboard. A postcard is perfect, cereal box is great.
Scissors
A light coloured, thin felt tip or a pencil or wax crayon
A thick marker or felt tip in a dark colour.

Anyone can walk through a postcard, you just have to cut the hole the right way. The longer the edge, the larger the hole. You need to make a really long edge for your hole.

Measurements don't need to be precise, but they should be fairly close. If you don't have a ruler to measure, test out your design in pencil until it fits.

Step 1. A standard postcard is around 10cm x 14cm, so cut a piece of thin card or really thick paper to this size. Using the pencil or light coloured pen, draw a rectangle 1cm in from the edges of the card.

Step 2. Now draw lines in the rectangle. Go across the card and space about 1cm apart. Every other line should continue outside the rectangle on both sides, right to the edge of the paper. Don't worry about an odd sized one at the end.

Step 3. Draw a line down the middle of the card. You can fold it in half to help find the middle.

Step 4. Draw another 2 lines down the page, around 1cm either side of your middle line/fold. Go over the vertical pencil line down the middle of the rectangle remembering NOT to go all the way to the top and bottom edge of the card.

Step 5. Take your big thick marker and go over alternate lines across the page - 1st, 3rd, 5th etc. Not the lines that go to the edge, just the other horizontal lines.

6. Now go over the lines that reach the edge, but ONLY go as far as the pencil line - NOT TO THE MIDDLE.

Step 7. Now cut all of the thick dark lines. Don't cut anything else. If you've gone wrong, check the Step 6 photo. Some of the cuts are much easier if you fold your card in half.

Step 8. If you folded your card in half to cut some of the lines, it will look like this one. Unfold it carefully.

Step 9. With all of the cuts correct, your card should look like this.... If you accidentally cut the wrong bit, use a bit of sticky tape.

Step 10. Carefully give your card a stretch...

Now all that's left is to step through your postcard!

Maths & Engineering: What is the smallest piece of card that you can walk through? Is there a better way to cut the card? What happens if you don't cut using straight lines?

We actually blogged about this back in Summer 2013, when 3 of our teenagers made much smaller cuts and much bigger holes in their postcards! 

You can find the first 5 Minute STEM Activity here - Fish In The Tank
2nd here - The Floating Arm Trick
3rd here - The 5cm World Challenge
4th here - Making Gluten