Science is all around us, in the natural world, in the construction of buildings, in the chemistry of life. The first thing to do is to encourage them to be observant. What do they see, hear, experience, taste, smell and touch. This broadens their physical knowledge of what is around them. Some will find this more interesting than others. Ask them questions but not as if they were being interrogated.
Children of all ages enjoy growing things like crystals. They seem to come from nowhere and increase in size. Learning to deal with something so fragile is also useful.
Understanding science helps humans to solve problems. Luggage can be weighed with a suspended broomstick, a kilo bag of rice and a hook to hold a suitcase. Without knowing it they are learning moments. This brings in words like fulcrum and sea saws. This is a introduction to physics.
Many people are enthralled by music. If the child is learning an instrument, perhaps something about how the sounds are made and how they are heard would be useful. Noticing the space between flashes of lightning and the crash of thunder during a storm offers insight into how those two things travel through the environment.
Magnets are always fun and hours can be spent working out how to produce different effects and the practical uses, such as finding small, lost metal objects like pins.
Knowing that salt and cold water will remove blood stains is teaching them some practical chemistry. The chemistry of cooking is also a bit magical. They learn to feed themselves nutritionally well, and that some simple chemistry makes wonderful changes.
Onion skins and other natural materials make dyes. An adult working with the children can encourage them to have fun looking up what plants are safe to use and what colors are produced. Dying fabrics to make toys or cushions gives them something they have made themselves and is always rewarding and treasured. This is an introduction to biology and chemistry.
How to alleviate the discomfort of cuts and bruises shows how plants can be used medicinally. Arnica eases bruises, calendular helps wounds to heal. These have to be bought preparations. At the same time cleaning wounds with antiseptics teaches them about infections and hygiene.
Many families have pets. Attending to the needs of the animals shows them that different species fit into different niches and need a variety of foods and habits. It’s no good feeding a lizard the same way as the dog. The fact that furry friends have worms, ticks, lice, and fleas is another lesson in the living world and how those problems are solved.
Without being aware of it, people use science all the time. Knowing how to achieve safe results with natural materials helps children to live in a safer world.