Easy Science Experiments for Preschoolers at Home

Preschoolers are already scientists. They drop things to see what happens, splash in puddles and ask “why?” about everything. Your job is not to teach them facts. It is to give them safe things to try and a few good questions.

Expect short attention spans. Five to fifteen minutes is a good session. Expect mess too, so work on a towel or a tray, and stay within reach throughout. Anything small enough to swallow is not suitable for children who still put things in their mouths, and nothing in these activities should be eaten.

How to run a preschool experiment

Keep the pattern simple:

Wonder. “What do you think will happen?” Accept any answer.
Try. Let them do the pouring, dropping or mixing.
Look and talk. “What did you notice?” Repeat their words back to them.

Do not worry if the prediction is wrong. Saying “Hm, I did not expect that either” is excellent science teaching.

1. Sink or float

Fill a washing-up bowl or large bowl with water. Gather a handful of safe objects: a wooden spoon, a plastic cup, a coin, a cork, a leaf, a metal spoon. Ask your child to guess “sink” or “float” for each, then drop it in. Sort the objects into two piles.

Words to use: sink, float, heavy, light. Do not expect them to link it to weight yet. Some heavy things float, and that is a nice puzzle for later.

2. Colour mixing in cups

Put three clear cups in a row and fill each about half full with water. Add a few drops of red, yellow and blue food colouring to separate cups. Give your child a dropper or spoon to move colour into empty cups and see what they make. Ask what colour they think red and yellow will make.

3. Ice rescue

Freeze a small toy in a container of water overnight. Give your child a tray, warm water in a small jug and a spoon, and ask them to free the toy. The warm water should be comfortably warm to your hand, not hot. They will discover that ice melts, and that warm water does it faster than cold.

4. Magnet treasure hunt

With a magnet around the size of a coin or larger, walk around the house together and test things: fridge door, spoon, wooden table, key, paper. Make two piles, “sticks” and “does not stick”. Supervise closely and keep small magnets away from anyone likely to put them in their mouth.

5. Shadow tracing

On a sunny day, place a toy on a big sheet of paper outdoors and trace its shadow. Come back an hour later and trace it again. The shadow has moved and changed size. Ask, “Where did the shadow go?” The lesson Why does my shadow follow me? builds on this idea.

6. Seed in a bag

Wet a paper towel, fold it into a clear zip bag with two or three dried beans, and tape the bag to a window. Check each day and draw what you see. It takes a few days to a week, and children love the surprise of a root. Our lesson on what a seed needs to grow goes further for slightly older children.

What to say

“What do you notice?”
“What do you think will happen next?”
“Show me.”
“I wonder why.”

Avoid correcting too quickly. If a child says the shadow “went to sleep”, you can say, “Interesting, where do you think it went?” and then show them with a torch.

Keeping it going

Pick one experiment and repeat it a few days later. Repetition is not boring to a three-year-old. It is how they check that the world is reliable. Take a photo or draw a quick picture and stick it on the fridge so they can tell someone else what they did.

Where to go next

Science lessons that need no materials is useful for the days you have nothing to hand, and how to answer why questions kids ask will help with the endless questions. Our home education page shows how lessons can fit around family life.