Families new to home education often wonder how it all works, but especially want to know how to go about planning lessons. In England, there is no need to plan lessons, or to take any kind of 'formal approach' to your child's education at all. In time, you will see what kind of style will best suit your family circumstances, and then everything will fall into place. Be relaxed, self assured and above all, enthusiastic! The most effective teacher is one who listens more than s/he talks. Take a gentle approach and your child will soon respond with ideas and inspiration. You simply need to be ready with lots of energy and resources to help you both find out more information on any given topic. If you can't find what you are looking for, or you need support in any way, please ask.

The following Theme Guides are meant to inspire you to tailor your own child's education around his/her interests, and also as a quick source of help for those times when your child's demand for education exceeds the rate of supply! Like anyone else, home educators suffer from coughs and colds from time to time, so it is useful to have something tucked up your sleeve just in case you ever feel too run down to be enthusiastic. Please ensure that your child is properly supervised where necessary, as some of the activities involve deep water, etc. You'll notice that, rather than organising learning by 'lesson type' (e.g. experiments, writing, art, reading, etc.), I organise into 'subjects' (e.g. astronomy, dinosaurs, etc.). This is because my children prefer to spend a whole day on a particular topic so that we can explore it from different angles, and then express what we have learned in different ways. Please tell me what you think of the Theme Guides. If there's interest, I'll add more as I find the time...

Buoyancy/flotation: How can large things float on water, when a little stone sinks to the bottom of the sea?

The Theory: The Archimedes' Principle states that an object immersed in a liquid is buoyed upwards by a force equal to the weight of the liquid displaced by that object. Thus, he concluded that a floating object displaces an amount of liquid equal to its own weight.

Kitchen Science Experiments: Take two identical pieces of modelling clay. Make one into a ball, and the other into a flattened boat shape, then place each of them onto the surface of a sink full of water. What happens?

Next, put one of your hands flat on the surface of the water, and make a fist with the other. Which hand is more difficult to push into the water?

Now, blow up a balloon and put it into the water. Does it sink or float? Can you push it underwater? Is it easy to push it downwards, or difficult? Watch what happens to the water level as you push down on the balloon. What's happening?

Finally, sort some objects into groups, depending on whether you think they will float or sink. Were you right? How can you use what you have learned to produce a set of rules to help you work out whether or not other things will float? Are there some materials that always float or always sink? Be careful, as there are often exceptions to rules! See if you can work out definitions for 'float' and 'sink' without looking them up. Also, as you notice similarities between things that float, you will become more expert in predicting what will happen when you try new items in the water.

Vocabulary: Find out what the words 'float', 'relative', 'displace', 'volume' and 'immerse' mean by checking an encyclopaedia or dictionary (how do these definitions compare with your own?). Can they only be associated with water, or can they be used in other contexts? (There is an good opportunity to go off at a tangent here. Also, if you have very young children, consider talking about the more advanced concepts in simple terms, and leaving the names for later - perhaps using the opposing concepts of 'float and sink', 'same and different', 'over and under', 'in and out', etc. instead.)

Storytelling: Encourage your child to help you make up a story, perhaps about an acorn that falls from a tree and is carried away on the water, or a group of children who sail away on an adventure. How about a magic island that floats on the water? Or children diving for treasure in a sunken galleon? If you or your child find it difficult to make up stories, try depicting the events with paint, pencil or collage and talk about the story as it unfolds while you work at your crafts.

At The Riverbank: Look for things that float on the water. Do sticks float? Leaves? Can you see something floating in the water to signal danger? Are there flotation devices nearby to throw to a person who has fallen in the water? (This can lead to a discussion about safety at the waters' edge.) Is there litter in the water? How will this affect the local wildlife? (Again, this can enable you to digress to a discussion about environmental/ecological concerns.)

Why do ducks float? A duck floats because its body is light compared to water. Air is lighter than water, and ducks have plenty of places filled with air. All their bones are hollow, and feathers trap air against the duck's body too. In fact, a duck's body has sacs filled with air like mini balloons to help keep it afloat!

At The Swimming Pool: If you lie flat on the water, you'll notice that, just like the boat-shaped piece of clay, you can float without trying. What happens if you wrap your arms around your legs and make yourself into a ball, like the other piece of clay?!

Remember when you were pushing your hands into the water at home in your kitchen sink? Well, the water was pushing you back! Whether you sink or float depends on how much water you have pushing against you. When you make yourself flat, you are larger, so more water is touching your body and pushing you back. When you curl up into a ball, however, you are smaller and there is less water touching you, so it cannot support your weight.

In The Bath: Mark a 'fill level' line on the bath with a non-permanent pen or a pencil, and fill the bath until the water touches the line. Now, get in, lie down and check the line you marked against the water level. Has the water level gone up or down since you got into the bath? Your body has displaced the bath water. That is, there's not enough room in the bath for the two of you! Long ago, there lived a great mathematician called Archimedes. Now, Archimedes was thinking about why some things float on water while others don't, when he decided to take a bath. The bath was filled to the brim, so when Archimedes stepped into the bath, he displaced some water, which ran over the sides of the bath. When he spotted the mess on the floor, he realised that it was all related to the problem he had been thinking about. He shouted, "Eureka!" This means "I've found it!" (Another opportunity to go off at a tangent - great mathematicians, life in Classical Greece, ancient history, mythology, etc.)

The amount of space an object occupies is called its volume. Just as the water level in the bath rose when you got in, and the water level in the kitchen sink rose when you pushed down on the balloon, any object must make room for its own volume by pushing aside or displacing an equal volume of liquid. Now, because the water is pushing back at the object, the weight of the object also has to be considered. As you may have noticed when you filled the bottles in the sink, the object floats when it has displaced just enough water to equal its own weight when on dry land. You've probably noticed that your drink will rise in the glass when you add ice, but why do you think ice floats?

Research/History: A famous ship called Titanic sank when it hit an iceberg. Find out where and how it was built, where it was going, and who was travelling onboard. (There is a huge number of things to do around this, for example: a typical day onboard Titanic, dressing up as some of the first class travellers, dramatisations, painting, museum visits to see items from the same era, etc. You could also watch one of the film versions and then compare the film production with the historical facts as we know them, or discuss what you both think of the director's choice of camera angles, the acting, editing, etc.)

More Advanced Ideas

Medicine: Find out about flotation therapy. What benefits are reported by researchers, scientists and users? What do you think of the use of such devices as flotation tanks?

Creative Writing and Art: Imagine you have volunteered to use a flotation device for a few hours. Write about your experience, or paint what you might see through your mind's eye.

Research/Environment/Trade/Law: When oil spills occur at sea, booms incorporating flotation devices can be deployed to divert the oil slicks, making them easier to remove from the surface of the water. Find out more about oil spills, the equipment used to clean them up, the impact on the local ecosystem, and any wider implications such as a break in the food chain, the impact of reduced stock to harvest for human consumption, etc. What will happen if the oil slick makes it to the shoreline? How long will the cleanup operation take? How often does this kind of disaster occur? What are the consequences for the company responsible for the spill?

Ancient History: Archimedes was military advisor to King Hiero and employed a number of devices to defend against the Roman siege of Syracuse. You can find out more from the work of a writer called Polybius, who would most likely have been able to talk to people who were in Syracuse at the time of that siege. Other writers - Livy, Plutarch and Dio Cassius - also wrote about the siege of Syracuse. Eventually, though, Syracuse did fall to the Romans. Why was Marcellus sent by Rome to take Syracuse, and how did he finally manage to defeat the Greeks of Syracuse?

While Archimedes was in Egypt, he invented the Archimedean Screw, which the Egyptians renamed after themselves. What did it look like, and what was it used for?

Geometry: What are the names of the thirteen Archimedean Solids and what do they look like? Try drawing or painting them, and if you're feeling ambitious, why not have a go at making them?! Some of these shapes have been used in sculptures and functional shelters. See if you can find examples.

Back To The Kitchen: Just as the volume of an object affects how far it sinks into a liquid, its density must also be taken into account when attempting to predict whether or not it will float. Fill a deep saucepan or bucket with cold water, and gently drop in an unopened can of Coke. What happens? Now drop in a can of Diet Coke and see what happens.

Why did they not behave in the same way? The answer is to do with the density of the sugars. Diet Coke contains a synthetic sugar and this particular one is less dense than water, and so the can floats. Regular Coke sinks because it is made with sugar, which is more dense than the water. You might be interested to find out more about synthetic sugars, and how they are used in our food. Have any side effects been reported by consumers or researchers? What are the benefits of using synthetic sugars in place of natural sugars?

Density is calculated by dividing the mass of an object by its volume. The mass is simply how much it weighs, and the volume is how much space it takes up. Thus, it could be said that density is to do with the amount of matter in a given area. Play with some fractions to see how density changes when you alter the numerator (mass) or the denominator (volume). You should find that small, heavy things have a higher density than big, light things. Compare a golf ball with a basketball, for example.

Assuming that your coke cans are regular cylinders (it doesn't matter that they're not in this case, as they are both the same size and shape), calculate each density to confirm your laboratory findings.

Geography/Geology/Ecology/Experiment/Mathematics: Just about anyone can float on the Dead Sea in Israel. What's so special about that particular lake? Find out about the reasons why people might want to visit the Dead Sea. How have sea creatures adapted to live in the water there? The Dead Sea shore is the lowest dry point in the world, and the water level is continuing to drop despite the fact that it should be fed by rivers such as Nahal David and Nahal Arugot. Why are the tributaries not making it to the sea? Where is the water going instead? What effect is this having on the landscape? Find out how the Dead Sea became so salty, and try devising your own experiment to copy this phenomenon using a bowl, water, table salt and an egg (try to float the egg!). What can you say about the relative amounts of each substance you need to add? Try the experiment a few times with different quantities of water.

Because It's Fun...! Let's go back to the Kitchen and do something a bit more exciting! For best effects, make sure you have an audience for this one! Take a bottle or container with a capacity of around 3-4 litres and pour in about 500g of baking soda then add water until the container is about three-quarters full. Swirl it around to dissolve most of the powder, then let the rest settle at the bottom. Add small amounts of vinegar to start a reaction to produce carbon dioxide bubbles. The gas you can see is given off by the reaction of the alkali (baking soda, also known as sodium bicarbonate) in contact with the acid (vinegar, also known as acetic acid) and select a few objects to place into the liquid, such as paper clips, raisins, pieces of spaghetti.

If you don't have access to the ingredients I mention here, you can see what happens almost as well if you drop a raisin into a glass of clear, fizzy drink (such as lemonade or carbonated mineral water).

As it races to the surface of the liquid, carbon dioxide gas collects under the objects, and when enough air bubbles collect to support their individual weights, one by one, each object floats to the surface. You will notice that some objects float to the surface quicker than others. What does this tell you about their relative densities?

Try working out the chemical formula to describe what is happening. Also, think about other circumstances when gases help us to float, or when we don't want them to! For example, how come divers have a container of gas strapped to their backs and yet still sink below the surface of the sea? The answer is very simple and is connected to the reason why they always fall backwards into the water when they dive from a boat.

I hope you enjoyed this learning guide. If you could spare the time, I would appreciate it if you could give me some feedback about it.