Preschoolers have an insatiable need to explore and understand things that adults might overlook. As marine biologist Rachel Carson said, children need an adult who can share this joy of discovery with them. Your family can share the joy of discovering science at home and in your neighborhood.
Go for a walk. Talk with your child about what you can see, hear, and touch. Look at clouds, smell pinecones, gently touch a caterpillar, see what’s under rocks, and listen to birds and squirrels in trees. Take walks when it’s rainy, when it’s sunny, early in the morning, and in the evening. Talk about how the experiences are similar and different.
Discover answers together. Children often know all the dinosaur names or notice small details in a leaf. You don’t need to know the name of every plant, but you and your child can investigate and answer questions together.
Care for animals, plants, trees, and gardens. Plant bulbs (flowers or onions) and watch what happens. Put toothpicks in an avocado pit and suspend it over a clear container of water. Visit it daily. Soon you will see a new plant growing from the top and bottom of the pit.
Find science all around you. Learn about physics by playing with tennis balls and soccer balls. Which ball bounces higher? Which one can be kicked farther? Learn about chemistry while baking cookies together. What happens when the ingredients are mixed together and baked in the oven? Ask your child to share his or her ideas about what happens and why. If your child asks a question you can’t answer, write it down so that later you can look for the answer together in a book, at the library, or on the Internet.
Source: http://families.naeyc.org/exploring-world-science-your-child