Key Water Ideas
I love teaching science with my students. I try to teach it in a way that is explorative, where I offer my students experiments that shape their thinking and deepen their understanding. For our unit on water, the main understanding that I want them to have is that water can change. Water can change from liquid to solid to gas. Water can change shape depending on its container. Water can change how it acts depending on the material it is with – some materials absorb water and some repel water.
Starting With Reflection
When starting any unit, I always start with a reflection on what the students already know about the concept and what questions they are wondering and hope to find out about the concept.
I also want to give my students a chance to just explore with the materials and write, draw, and discuss their observations. It was interesting that some students said the water smelled salty, when I used fresh water for the observation. I wonder if they associate salt with water because of the ocean and when they couldn’t smell anything, felt they should write what they know water smells like. I definitely want to think about this for next year.
After exploring with the materials, I offered a few experiments to help guide their thinking. After each experiment, the students wrote and drew their observations and we discussed them as a class. These experiments below were testing how many drops of water could fit on a penny without spilling over (they got to about 20!) and which types of material would absorb water and which would repeal water.
The other experiments involved the change in states from solid to liquid. Students were asked how to melt ice the fastest and they tried a few methods (From holding the ice in their hands to putting it on the heater to putting warm water on it). Students also watched how long it took ice and snow to melt and how much water would be in the cup when it did melt (most students thought the water would fill the same amount of cup as the ice and snow).
Our final experiment was whether objects would sink or float in water. Students first predicted what would happen and then watched if they were right or wrong! We had a great discussion on how scientists love when they are wrong because it teaches them important information!
Finally, we ended with an exciting activity that combined a lot of the knowledge we had learned this unit. Students were asked to build a boat as a team. They had to plan their boat design, build it, and then test it in the water. Students tested whether it would float and then, if it did float, how many pennies would it hold before sinking. I put out many different types of materials to choose from. Many students included sponges because they knew sponges float. However, when absorbed with water and with pennies placed on top it becomes very heavy very fast and sinks. The students reflected and wanted to revise their creation and build a new boat without sponges the second time. We used the book Who Sank the Boat? by Pamela Allen to introduce the activity.
Have you taught water before? What was successful for your students? Let me know in the comments!
All of these activities and response pages can be found in my water unit from my teachers pay teachers store.