Structures and Den Day

Arrival Craft
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Making paper houses or tents (http://www.jesus-without-language.net/priscilla-aquila-acts-18-make/ or http://babbledabbledo.com/wp-content/uploads/2013/10/Paper-Houses-Template-BABBLE-DABBLE-DO.pdf)

 

Introduction

We’re going to be talking about structures today and why things stand up.

 

Individual Task

Give out wooden skewers and polystyrene balls, each table needs to make one triangular based pyramid and one cuboid. The children can clearly see the vertices of the shapes.
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If we make a triangle shape, it will be stiff even if the joints let the sides rotate. If we make a square shape, the joints have to be stiff for the square to keep its shape. If you push a corner of the triangle in any direction, you push and pull the sides, and they hold the corner still. In a square, they don’t unless the corners are stiff. It’s easier to make stiff sides, than stiff corners.

 

Using paper building blocks (https://babbledabbledo.com/science-for-kids-paper-building-blocks/), build a tower.
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Break for Drink and Snack – in aid of Save the Children’s Den Day, we will be building a big den to eat our snack in and all donations will be going to Save the Children.
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Gather Together

Buildings are made of lots of different materials, we’re going to do an experiment to look at some differences between different materials and how they react to stress.

I’ve got three rods which are all the same diameter (4mm knitting needles made of bamboo, plastic and stainless steel).  I am going to attach weights to them and mark on this paper how far they bend.

Set up the first rod, attach it firmly in place, measure 20cm along the rod and tie a string to hang the weight. Which rod bent the most? Which one bent the least? Which material would make the best hook?

Add greater weights and see how much weight must be added to take the material past its ‘plastic point’ where it will not spring back after the weight is removed.

 

Final Challenge

We’re going to try building with bricks now. I have some miniature bricks and mortar so that we can build some teeny brick walls.
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Electricity

Middly found some torch kits online and he wanted to have a go at making them, so I ran a session about electricity to give us a good excuse!

I wasn’t actually very pleased with the kits that arrived. I found them poor quality and we had to fix them before the children were able to make the torches, so I would rather not give a link to the site from which we bought the torches. We won’t be using them again.

After a bit of quick work at home to prepare simple kits, all the children were able to make little torches.

Once the children had made the torches, we talked briefly about the importance of completing electric circuits.

For our next activity, I wanted to do a quick experiment to identify good conductors of electricity. I gave each child this instruction sheet ElectricityExperiment and all the required supplies. The children tested a few common household items for conductivity.

We talked about what objects conducted electricity well.

I tried to demonstrate why metals are such good conductors of electricity. I showed the children a tray with tennis balls stuck to it, and explained that the tennis balls represented the nuclei of metal atoms. Then I tipped a bag of small polystyrene balls onto the tray and explained that in a metal the electrons are not bound strongly to their nuclei, but instead are free to move in a ‘sea of electrons’. I tipped the tray slightly and the polystyrene balls ran from one end of the tray to the other. I explained to the children that it is the relatively free movement of these electrons that allows electricity to flow so well through a metal.
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I found this craft on Home Science Tools. And I thought it would be a perfect addition to our electricity session. The children taped an LED and a battery to the top of a sheet of card, they attached hanging wires: one to the LED and one to the battery. Then they wrote quiz questions on the sheet of card, with the answers laid out so that they were not directly opposite the questions. On the back of the card, they attached the questions to the correct answers with a piece of wire held between two paperclips.
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Birds (again)

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We’ve already had one session on birds here. But Middly has been doing the RSPB Wildlife Action Awards and, as part of this, he wanted to put on a play about birds at Science Club. So I set up another session on birds.
This time our opening craft came in two parts. Some children made masks for the bird play (see above) and others used card and split pins to make models showing the insides of developing eggs.

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Middly and some of his friends performed Middly’s play about birds. BirdsPlay

We brought along some bird books so the children could try and decorate the outside of their eggs to resemble real bird eggs.
We finished off with dissecting owl pellets. I downloaded a sheet (from the RSPB) to help us identify the bones, which we found a bit tricky! But, it was lots of fun, even if some of the children found it ‘icky’. We soaked the pellets for forty minutes in cool water, then  I gave the children wooden skewers to tease apart the pellets, which worked really well.

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