Earth Science - Rocks and Minerals

This was the third in the series of earth science sessions that I have put together for one of the HE groups that we go to. The first was to do with fossils and last month we looked at plate tectonics and the structure of the earth. This month we looked at rocks and minerals. I passed around a piece of granite to look at and told the children that it was a rock and got them to describe what they saw. They identified different coloured flecks in the rock, some shiny, some dull - I explained that these were minerals and that minerals were the ingredients of rocks. I told them that granite was an igneous rock, which means 'made by fire' and how igneous rocks looked different - we compared granite and pumice and talked about how the granite had cooled slowly as it was pushed to the surface, allowing the different minerals time to clump together, and that the pumice had cooled rapidly after being blown from a volcano as molten lava and so the minerals had stayed mixed together, giving the even tone.

We went to the table and I used wax crayons to explain and demonstrate the different types of rocks. There are many permutations of this idea around on the web and as I haven't used one specific plan so I haven't credited it to anyone in particular. The demonstration requires a heavy based pot with a depth of just boiled water in it and it went like this:

• Sedimentary Rocks are rocks made from layers of rock particles, dust, sand and mud that filters down through oceans and lakes to the bottom, and becomes pressed into layers. The children were familiar with this concept from the fossils session. I had a bag of grated wax crayons as the particles and pressed them into a small foil cake tin to show how they form into sedimentary rock.
• Igneous rocks - these are made when minerals are melted due to the incredible temperatures under the earth's surface - I broke crayons up and put them into another foil container and floated it on the water and left it until the crayons had completely melted (see picture above where they are partially melted).
• Metamorphic rocks - these can be made from sedimentary or igneous rocks or a mixture of both, where they are changed by the immense heat and pressure and the length of time they are exposed to these forces under the earth's surface. To do this I put some of the sedimentary rock I made, some pieces of an igneous rock I had made earlier and some crayon pieces and floated them in a foil tin on the surface. After they had partially melted, i took the tin out and pressed them down with a spoon to represent the pressure they would be under - the children could see that the crayon pieces had changed from what they were.

We then went on to investigate how minerals are told apart by minerologists - by their different properties. I set up 'investigation stations' with a poster of printed instructions (these were intended that they be done by the children with their parent to help read and guide them.

Station 1 was Moh's scale of hardness, or the scratch test.......

Station 2 was the streak test, looking at what colours were left behind by the minerals when dragged across a porous surface (AKA the back of a wall tile begged from the local tile place!).

The pyrites surprised faith as it glittered like gold but left a greeny black streak! 

Station 3 was the magnetic test - only rocks with heamatite in will show attraction to the magnet - I guess they found one!

Station 4 was an acid bath to test for the presence of calcite in various rocks - I have to apologise to the resources library for the strong smell of vinegar present in some of the returning samples!!

The session didn't work so well today as it has previously. There were more families there and therefore a lot more background noise from the children that chose not to participate which caused me to have to almost shout over it at times and distracted some of the children from concentrating on the session. I chatted about it with the group organisers and we have a couple of ideas to try next time to make it work even with a larger number of families attending the group. There are some fabulous 'foodie' demonstrations to use to illustrate how the different rocks are made - I wasn't able to use them this time due to allergies in the children coming to the group, but am saving them up for when it comes up again with my children!!

There is much more detail and a scripted plan, as well the instruction posters for the mineral investigation stations, available as googledocs to download, print and use here:

• Earth Science - rocks and minerals
• Mineral Investigation posters

Learning About the Digestive System

Next up in our series about the human body, we investigated the digestive system. This didn't involve the most visually impressive set of activities and experiments but they were very effective at showing the girls the steps involved. We started out sitting down with a biscuit to eat. As the girls bit into and chewed their biscuit I asked them to think about how they ate it, what was happening to the biscuit and which parts of their mouth were involved. They were quick to identify that teeth crunched up food and their tongue pushed it around the mouth. We simulated this with a dry cracker in a ziploc bag to snap and crush as the teeth do. As the girls worked on 'chewing' the cracker, I asked a few questions to lead them to think about how the food changed from dry and crumbly to wet and mushy in their mouth and how that made it easier to swallow. This is their saliva glands working.

The tongue pushes the masticated food (the girls loved that word!) to the back of the mouth and the throat where it is swallowed. It travels down the oesophagus, down which rings of muscle contracting one after the other create a 'wave' of movement that pushes the bolus down to the stomach. We simulated this with a plastic Easter egg inside a pair of children's tights (idea from the science matters website). The girls made rings with their fingers and contracted them above the plastic egg, pushing it down the leg of the tights.

Once the food has arrived into the stomach, strong muscles in the stomach wall contract to churn and mash the food into a pulp that is slowly fed into the small intestine. Acidic juices are secreted onto the food to help break it down. To simulate this we added some soda water to the cracker in the bag and continued to churn the contents into mush.

We moved on in the journey of the food bolus into the small intestine. As the small intestine is so long, we measured out the approximate length of 6.7m with a piece of red wool and snaked it backwards and forwards on the table. The girls also tried stretching it to see if it was as long as our house! We talked about how the food is broken down even further with the assistance of the gall bladder, pancreas and liver into it's smallest components to allow the body to absorb it and use the nutrients, carbohydrates, fats and proteins from the food. The girls remembered how the capillaries run very close to pick up oxygen from the lungs from when we looked at the cardiovascular system, they linked it to the small intestine and asked if that was how the nutrients were picked up - I was pleased they were linking previous knowledge to this session. It takes around four hours from when food is eaten to it being absorbed and used by the body. The final part of the journey is the large intestine where the last of the nutrients and much of the water is reabsorbed.

To show how effective the use of acidic secretions is in breaking down food, the girls put a whole sweet into two jars and a crushed up sweet into another two jars. To one example of each they added water and to the other example of each they added vinegar as an acid. We left them for a few hours without agitating the jars at all then came back to see what had changed......

The jars containing acids had clearly had a lot greater effect on the sweet than the jars containing water. the crushed up sweet in the acid had completely gone, leaving a fluffy pinkish residue on the surface and sugar crystals on the bottom of the jar, whilst the water had only managed to liberate a few grains of sugar from the crushed up sweet. It was a simple but powerful way of demonstrating the need for acidic secretions in the digestive system.

Whilst waiting for the acid to break down the sweets, the girls coloured a picture of the digestive system and sellotaped their woollen small intestines onto the centre. We added them to the body outlines we have been making through our human body studies.

Baking with Toddlers

I have to confess that baking with a very small child is not top of my list of relaxing activities for a Sunday afternoon.... however I try and bake with Idris (just coming 21 months as much as I can as he really enjoys it! I chose scones to make last week as it's a good, messy hands-on mix to make with lots of processes to try...... He enjoyed rubbing the butter into the flour......

.....stirring the sugar in.......

....cracking eggs with a little assistance......

....rolling out the dough with a lot of assistance, and the most beautifully sensorial marble rolling pin in the world!......

..... and independently cutting out scones from the dough.

Amusingly enough he wasn't very keen on them when they were cooked, even with jam on! Thanks to Eve for the brilliant photographs as photography and toddler baking at the same time really IS a step too far!

Learning About the Skeletal System

We started out with this life size printable juvenile skeleton, cutting it out and piecing it back together on another life size body outline that we drew - I think we might make these into a huge book when we are done with our human body science studies. Whilst we pieced them together we chatted about the skeleton and I asked the girls what they knew about the skeleton and what they wanted to know. As usual, there were some answers that surprised me!

We talked about the functions of the skeletal system, with a few leading questions and some knowledge from our previous sessions on the cardiovascular system the girls were able to summarise that the skeletal system provides a frame, protects vital organs, manufactures red blood cells and allows movement in conjunction with the muscles.

I reminded the girls about one of the functions of blood - transporting nutrients and minerals around the body and explained that the bones were living and had a really good blood supply. Eve jumped in and asked if it was so the bones could grow..... yes, and repair themselves, I asked her if she knew what the most important  mineral was for bones and she knew it was calcium. We did a little experiment on some chicken bones to show how important calcium is. The bones were washed and dried and the girls tried bending them to see how strong they were. They put them into a jar full of vinegar and we left them for a few days. When we brought them out they were really bendy (shown above held in cling film as the girls didn't want to handle them without it!). It was amazing just HOW bendy they were without the calcium!

The next day we built a 1.2m high cardboard skeleton (I got it on offer from The Works at Christmas for a lot less) and as we did so compared and categorised the different types of bones - long bones, short bones, flat bones, irregular bones and sesamoid bones.

We moved on to looking at the function of the long bones in producing red blood cells for the body. we made a model inspired by this post on the blog 'science matters'. We started by rolling some red fabric to be the red marrow in the centre, then rolled a piece of yellow dish cloth around it to represent the fatty yellow marrow around it.......

...... we added a piece of natural sponge around that to show the honeycomb structure of the spongy bone around the yellow marrow. Lengths of red and blue embroidery floss represent the arteries and veins that bring a rich blood supply to the red marrow and remove by-products and red blood cells....

..... to finish up we wrapped white paper covered cardboard tube around the sponge to show the dense bone which is the final layer and around the outside.

As a final session, we talked about how bones and muscles work together to allow movement. There are different types of joint, we talked about the major ones of ball and socket, slightly movable such as the vertebrae in the spine (below, idea came from here)......

..... and made a model of the elbow hinge joint, with red balloons to show the muscles contracting and relaxing, instructions can be found here. We actually did most of this a few weeks ago but there was a short delay before we could complete our hinge joint after I realised that you really can't blow modelling balloons up without a pump...... and then I had to locate the infrequently used pump!! I was really pleased with how well the children remembered the information. We recap at the beginning of each session and then build on that information, linking it together and making it relevant to their own bodies, it was good to see them recalling and using the things we had learned previously.

The google docs printout of this topic with all four sessions full of all the information that we went through is available here! I hope that you find it useful!

The Theme for the Week........ Listening!

This week I have been listening to birdsong, listening to the girls ignore most things I ask them to do, listening to my own body telling me it needs something different and listening to terribly sad news from Boston and Texas on the radio whilst decorating the children's rooms still. My prayers are with the victims and their families as well as the rescue workers, medical staff and investigators. 

The birdsong was in the garden of friends of my parents, where Dewi was doing some tree felling for them. The children had a wonderful time, the girls used thin branches to build dens and made dinner from the catkins, and Idris played with everything he could lay hands on. He helped to load the sawn logs into bags (above)....

 ..... he climbed in and out of the bags and giggled whilst Allan swung him round in it.....

 ...... the girls used the pile of twig sized branches as a trampoline.......

......Idris did a bit of impromptu pouring with the dregs of my tea.......

...... and was finally allowed to try out one of the tools that he had been coveting all day without being allowed to play with........

 ....... as well as a bit of tin carrying, these were tricky to pick up together and Idris had to try a few different techniques before he had any success! It was nice to see him busily engaged in the hard work of learning about the world. He had been unwell Monday and Tuesday with a high temperature making him feel miserable so good to see him back to his best.

The girls have been argumentative and rude with a lot of bickering over the last week. We have managed to nip some of it in the bud but it is always a multi-step approach when things get out of hand and will take a little time to get things onto a smoother path again. I have used a 'time out' discipline technique with one of the girls that I'm not a fan of, but as nothing else over the past few weeks has worked to get through to her about an aspect of behaviour that was really unacceptable, we decided to try it. She went into time out twice for the behaviour in one day, and we haven't seen the behaviour since! 

The issue of chores has reared it's head again as it does every so often with complaints about being asked to do EVERYTHING and dragging their heels when asked to do something or simply walking away and not doing it. I have responded by asking them to do more, and us all doing it together before moving on from a mealtime and it seems to work! I'm considering implementing some kind of chore card system to spread the load without having to verbally ask time and again, not sure though!

As well as listening to what the girl's behaviour was telling me, I have had to start listening to my own body telling me to take note of being 25 weeks pregnant! When I was expecting Idris, I could sleep til 7am with the girls waking about 7.15-7.30 but as Idris wakes up around 5-5.30 am I am getting less sleep and also finding that I often can't rest in the day when I need to. I have a few ideas in mind to help me get the rest my body is telling me it needs so hopefully will get things in better balance soon. I think next week's focus will be on little old me with a few of the other things I am working on on the back burner for a few days!!

A Deceptively Sunny Attingham!

During the real cold snap recently I decided that we would wrap up warm and go to Attingham for the first time this year, another National Trust property that we love to visit. The weather report promised sunshine and silly me thought that it might take the edge off the zero degrees temperature promised alongside. So armed with a flask of home-made soup we set forth...... and no, the sunshine didn't warm us, as the bitter northerly winds sweeping across us made it feel well below zero!! Ah well, nothing for it but lots of running around, climbing and jumping off things then! The girls challenged each other to cross a little stream by increasingly wobbly log bridges set over it. I was amused until I remembered that I had no change of clothes and considered how painful the whinging walk to the car might be with a wet through very cold child!!

Scarves were made into flags on poles.......

Tree trunks were made use of.......

Snowy log piles were scaled.......

Ice was broken......

Water was splashed......

And the lovely gardeners shared their bothy and stoked the fire for us to warm our cockles by as we supped our soup and warmed up again!

Eve was taken with this simple display of terracotta pots......

I wonder if the indoor displays were getting more attention than normal due to the frozen conditions stopping play in the kitchen gardens at Attingham also??

Fuelled by hot soup and a sandwich, Idris was much bolder and ventured far off the path into the woods, setting off a determined pace at one point in completely the wrong direction after a lovely labrador puppy that he took a fancy too..... He made me run to catch up with him!!!

RHS Benchmark Scheme Progress

We have continued to work towards RHS level 3 as weather has allowed!! In the picture above, Eve and a (reluctant) Faith are measuring the raised bed. It was 3m20cm by 1m Eve said and she marked it out on a sketch of the bed and then set to work designing the veg planting plan, using symbols for the different veggies that we want to grow, and writing names alongside them. 

We have spent quite a bit of time talking about what we would like to plant, each member of the family has had their own input. I want to grow sweetcorn, courgette and spinach, Dewi wants to grow runner beans and lettuces, Eve wants to grow snap peas and strawberries and Faith wants carrots and radishes. I think that the girl's choices are swayed by previous years when we have grown the same. The veg beds become an outdoor larder for them with the girls harvesting baby carrots and snap peas for a quick munch whenever they feel peckish. It is rare that we ever actually cook any carrots or snap peas from our garden!! As well as talking about what we wanted to plant, we talked about where to put it. I had thought about going through the principles of 'square foot gardening' with Eve but it is fairly technical with spacings for each plant and I didn't want to dim her enthusiasm for planning it out by making it into a chore! Eve was confident that tall plants needed to go at the back of the bed and smaller ones at the front so that they all got adequate sunshine. I only made one tweak to her plan, which was that the sweetcorn plants needed to go in a block rather than a row or they wouldn't produce any ears of corn! I'm going to wait a little to introduce the idea of successional sowing and planting out later in the year in spaces vacated by summer veg, I think that that lesson will happen naturally!

As soon as the temperatures came up a bit more, we planted out the long-overdue sunflowers and snap peas that were still on the lounge windowsill begging for more space! Faith carefully spread hers out by placing the biodegradable pots equal distances apart by eye along the back of the bed.......

She dug a deep enough hole.......

.......made some tears on the bottom of the pot to help the roots make progress downwards.......

....... and carefully firmed the soil around the little pots before watering them in.................

This is Eve working at the front of the bed, carefully planting each pea plant after spreading them out along the bed at equal distances. She has plans to put the nasturtiums (edible flowers for salads etc) in between the peas, and has elected not to stake them as she plans for them to tumble over the side instead. I think this is a good idea and is based on previous year's observations where our pea plants have done very nicely tumbling around without support of any kind!

I am recording this as evidence of section one (some children are participating in the design of the garden), section three (the garden being used as a resources to teach more than one curriculum subject - measuring and areas in working out the size of the bed), and as evidence of the children carrying out gardening skills.