Bring your preschoolers outdoors and show them an example of a naturally abundant object such as a pine cone or a leaf. Ask them to collect samples of this item around the playground. Give them a small paper bag to store their findings and round up the group five minutes later. Arrange the group in a circle and ask the children to empty the contents of their bags. Discuss the similarities between the object you originally showed and those collected by the children. This activity requires children to memorize the defining characteristics of the original object and apply them to their search for something identical or similar.
Building small shelters out of twigs and leaves builds preschoolers' spatial reasoning and understanding of cause and effect. Instruct each child to find a tree or clearing on the playground. Ask them to use natural items on the ground to build a small house for a woodland fairy. The children must only use safe objects that are readily available such as leaves, acorns and twigs. While building their houses, children learn how the weight of the acorn affects the leaf and how changing the position of the items creates differences in the structure.
Take a nature walk with your preschoolers. Ask them to raise their hands and point out all the green or red or brown objects they see. Start with one color and switch halfway through by saying, "OK, remember how we were looking for all the green objects? Now I want everyone to raise their hand when they see something brown." Adjust the colors based on your particular school's environment; for example, use colors from the playground or store signs if you're in an urban environment.
One of the simplest, yet often overlooked, cognitive-developing games is pretend. Preschoolers quickly assume roles and develop scenarios without adult direction. Such games may appear childish to the untrained eye. Child development experts confirm pretending actually builds an important set of cognitive skills, including memorizing the role of characters, spatially negotiating building a fort and practicing grown-up speech when they pretend to be adults.