An experiment is like a special kind of game where you try to find out new things. Imagine you have a box of crayons, and you want to see what happens if you mix different colors together. You might mix blue and yellow to see if you can make green. This is like an experiment because you are trying something new to see what happens.
Another way to think of an experiment is like being a detective. Detectives look for clues to solve mysteries. In an experiment, you are looking for clues to answer a question. If you want to know if plants grow better in the sun or the shade, you might plant one in the sun and one in the shade and watch what happens. You are being a detective by figuring out what makes the plants grow better.
Experiments are also like baking a cake. When you bake, you follow a recipe, but sometimes you might try adding something extra like chocolate chips or a new spice. You do this to see if it makes the cake taste better. In an experiment, you are following steps to see what changes and what stays the same, just like when you bake a cake.