Your young learner should be given opportunities to explore their senses. In the past I have collected film canisters and added cotton balls to them. I then use oils, extracts, or perfumes to scent the cotton balls. I allow the child to smell what is inside and guess what it is. Then we record what we think and check later. You can also gather foods that cover all the taste senses and have them tell you which taste it falls under. My favorite was sour! It helps to have pictures of each taste so the kids can understand the word if they don't already (some kids may not understand bitter but understand that medicine can be bitter).
Let your young learner touch and explore. Many people are worried about the mess it will make, but it’s important to allow them to touch and feel things. Finger paint, squirt shaving cream all over your table, make gel bags for them to squeeze, make dough, make goo (http://littleshop.physics.colostate.edu/Try%20At%20Home/goorecipeone.htm). The messier the better. Use vivid words when you are discussing what it feels like.
Start having your young learner collect things from nature and describe them to you (the pinecone is brown, this rock is heavier than this rock, this stick looks like a Y). You can have them draw a picture and write about it. You should translate what they wrote under what they wrote.
Throw different tools in the sensory table. Have items to view with a magnifying glass. Have them draw a picture of what it looked like without the magnifying glass and another of it with the magnifying glass. Ask why people need to use magnifying glasses. Let them read a book using one. Let them stick thermometers in snow or water and record what they see. Ask why it went down when stuck in snow, but up when it was placed in boiling water (you obviously need to put it in the boiling water-but they can still look to see that the temp went up). Ask about other things that would cause the temp to go up or down.
By this age, your young learner should know if something is living or nonliving. Go outside and have them find things that are nonliving. Ask them why it’s nonliving. Do the same for living things. Gather pictures of living things and ask them to group them. What do these living things have in common? What is different? Once they know the difference between living and nonliving start to discuss the needs of living things. What is a need? What is a want? What happens if we don’t have something we need? What if we don’t have something we want? Gather pictures of needs and wants. Have your young learner put them in two piles by wants and needs. Make sure you discuss each item and why it’s a need or want.
One of the most favorite activities was using magnets. Place metal items on a table and place a magnet under. Show how the objects move. Show how you can pick metal items up with it. Show what happens if you try to pick up plastic or paper items. Why doesn’t it work? Hide metal items in sand and let them find it with the magnet.
Next, work on gravity. Stand on something stable and drop items. What happens if you drop a book and toy car at the same time? Have them feel each item and guess which will hit the floor first. Make a prediction and record it. Talk about the fact that scientists always make a guess as to what will happen first. After they guess, try it out. Were they right? Have them record what really happened.
Weather is a big part of preschool. After I did calendar I would always do weather. Keep a chart with pictures of the different kinds of weather. You can do it by the month or by the week. Compare today’s weather to yesterdays. Have a spot available to guess what tomorrow will be like. Talk about what you should wear in that kind of weather. You can show pictures of weather and have them draw people wearing the appropriate clothing.
This is just the beginning of science and your young learner. The world is your classroom. Go outside and use it!