After a few weeks of kids getting sick and not really doing co-cop, this past Wednesday we had a really good one learning about water. I hadn’t planned it this way but I feel that this semester we ended up doing mostly primary curriculum in introducing some science and history concepts. It all worked out because half the children are 5 year olds. Next semester they’ll be 6 and then we can do more advanced science. We will also be adding history to our co-op.
At the beginning of the semester, the children learned about solid, liquid, and gas. We explored air a few weeks ago. So we’re ending our semester exploring water.
For the topic of water, we started by reading a story by 林良, a very well known and prolific author in Taiwan. The book is called 小紙船看海. It’s one of my favorite books because the children can learn to fold a paper boat after reading. I picked this book because it’s kind of water related.
The story follows a little red boat from the country and a little white boat from the city in their journey to the sea. Thank goodness I looked at the book of water experiments before co-op. Half way through reading, I said, “Hmmm! I wonder how a cruise ship is able to float on the water and not sink?” Perfectly tied into the experiments we were doing that day and totally a on-the-spot brain fart. The best kind!
Next, I showed the children a book on experiments they can do with water that I had checked out from the Oakland Library： 進入科學世界的圖畫書 水. I really love this series as well because it is really easy to read and simple to duplicate experiments. We have some of the books at home but not all. Definitely something on my to buy list. We quickly went through all the available experiments. I didn’t want to give them an idea of what they will “discover” so I just read them the name of the experiment. The children had to choose 3 out of the 5 we could do. Of course, the kids chose the most interesting sounding ones. “水是大力士” (Water is a hulk), “水底火山” （underwater volcano) and 吊冰塊 (fishing for ice cubes)
Thank goodness we limited it to 3, because the whole thing took much longer than I thought. I always forget children are process oriented and not goal oriented. Obviously for me I’m thinking, just following instructions, do the experiment, move on to the next one. Not so for the kids. It took us maybe 1.5 hours total to get through all three.
1. Experiment #1, Fishing for Ice Cubes 吊冰塊
For the first experiment Fishing for Ice Cubes 吊冰塊, we got some ice cubes, 100% cotton string soaked in water, and salt. The children put the string on the ice cube, sprinkle some salt on top of it, and waited 30 seconds. Voila, they can pick up the ice cube with their string!
Of course, the children only wanted to repeat this experiment 5000 times while the moms tried to remember why it works. Salt melts ice, which then reforms over the string. That’s why you need water in the string as well. Though scientifically I think it’s explained by saying salt lowers the freezing temperature of water. I think for Thumper, I could actually follow up with some chemistry lessons on why this is so.
By the end, we kind of figured out the nuances of this experiment. After a few tries, the string is saturated with salt and it doesn’t want to stick anymore. Sprinkling too much salt or too little salt also makes it not stick.
Here is another write up of the experiment online in Chinese.
2. Experiment #2, Underwater Volcano 水底火山
This was a quicker experiment because it was done by me more than the kids. One thing adults are often afraid of is children making a mess. Or, in my case, Thumper taking some idea and running away with it and doing something wholly different, as she did in this case. Next time, I will probably try to set it up so kids can do the whole experiment themselves. But I’ve yet to figure out what I should do when the kids take it in a different direction and ends up just playing with the material.
For this experiment, you put 3-4 drops of food coloring into a small jar of hot water. Close the lid and immerse this hot water into a bigger bucket of cold water. Once you open the lid of the small jar, water will float to the top, because warm water is lighter than cold water. Why? We don’t really know. But it’s okay, I have to remember I don’t need to know. Get the kids interested and have them research why.
We repeated this experiment 3-4 times, with different food coloring each time. At the end, the kids wanted to add 3 drops each of 3 colors. I thought that was too much food coloring but it turned out well because you actually see the volcanic “eruption” much better.
3. Experiment #3 水是大力士 Water is a hulk
For #3, we gathered some large stones, put it in a plastic bag, and tried to have the children lift them. It was great especially for the 2 year old, who definitely could not lift the bag. Then we added a lot of water in a tub and have the children all try again. This time it was much easier.
This experiment shows the buoyancy of water. We didn’t talk about this much but I think definitely follow ups can.
I learned that it is important to involve the children in the experiment process. Otherwise, if the parent is busy prepping, the children will lose interest and run away to do other things. And of course, they also lose interest gradually as time goes by and they lose focus. I thought about prepping everything before hand and just have the kids read an experiment card to try and do everything themselves. But I prepped last minute as I usually do. Thankfully the children aren’t all reading anyway so it’s not quite appropriate. But I think definitely a possibility if the children get used to the routine of doing experiments.
- buoyancy – 浮力