Color My World
In our effort to give intellectual stimulation to young minds, we sometimes lose sight of the fact that preschoolers are incapable of understanding intangible concepts. But while you may find it much too hard to teach a child the theory of relativity you can teach them about science by taking them outside and showing them examples of how nature manifests in the world they can touch, see, smell, taste, and hear. Kids love the out of doors and you can exploit this natural predilection for nature as a means to teach them about their five senses.
Seasonal Items
Start by bringing preschoolers outside. Ask them to look for items that are found in nature and not man-made. You can make the task a bit easier by narrowing this down to things that represent the season such as things that are green or perhaps the fallen acorns and leaves of autumn. Then you might introduce another concept by asking children to find one heavy object and one lightweight object plus some leaves. Now you might start a discussion about the sense of touch by describing the way these items feel.
At this point, you will want to bring the children back into the classroom with their items to discuss the concepts they have learned. You can give them washbasins filled halfway with water (make sure you watch them at all times or have a trusted helper to do this for you), and have the children place their gathered objects into the water to see if they will sink or float. Do all heavy items sink?
Busting Expectations
Some items may surprise them by falling outside of their expectations: Why does an apple float? You might explain that items containing a great deal of air will float even when they are heavy.
Now you can pass around the leaves. Have the children look at the leaves and hold them up to the light. Point out the veins of the leaves and explain that these are small pipelines for carrying water to the tree or plant. You can point out that people have veins, too, and discuss the fact that human veins also serve as a conduit, that they carry blood and oxygen to all parts of our body. If there are leaves from deciduous trees among those that were gathered, use the opportunity to discuss the different types of trees and their life cycles.
Last but not least, incorporate the gathered leaves into an art project that can be brought home or displayed within the classroom.