Children are naturally curious. They find wild delight in tiny ants crossing the sidewalk, they take pleasure in pulling out all the contents in your kitchen cabinets, and they love sticking their hands into gooey mud and rubbing it all over themselves and the dog. Children want to learn and explore the world around them – and it is our job to foster this creativity by encouraging them to think critically about the how’s and why’s of the world. It is your job to enlighten them in the world of science.  

Scientific Method

The Scientific Method is a tool to help organize a child’s natural curiosity of the world; a set of general guidelines or steps used by most scientists (and yes, by completing experiments your child is a scientist) to arrive at a conclusion. Here, we simplified the steps for Pre-K to elementary level learning.

  • Purpose – What is it you want to learn about?
  • Hypothesis – What do you think will happen?
  • Procedure – How will you arrive at your results?
  • Results – What actually happened?
  • Conclusion – Was your hypothesis correct?

Experiment Time!

Introduce the topic:

“Bacteria are the simplest organisms that are alive. There are many different types of bacteria; some are good and some are bad. Bacteria can live in many different environments, but reside on almost all surfaces in our home. When your Mom, Dad, or teacher asks you to wash your hands, they want you to do this to get rid of “germs”, bacteria, and viruses.” YouTube can serve as a different mechanism for teaching.

While you are introducing the topic start probing your child with open ended questions. “What do you think bacteria look like? Where do you think they might grow? Why do you think we want you to wash your hands?”

Let them ponder the questions; you don’t necessarily have to correct them; science is after all, a series of mistakes until you finally get it right. After you’ve explained some about bacteria and asked them thinking questions… let’s get started.


  • Kit from Amazon
  • Petri dishes – included (shallow dish filled with agar which is used to grow cultures of bacteria)
  • Sterile Cotton Swabs – included
  • Distilled Water
  • Sharpie
  • Masking tape or painters tape

Insert the Scientific Method:


To explore and learn more about bacteria and where they grow in your house.


Where does your child think bacteria will grow the most? Try to let them arrive at their own natural conclusion, not leading them in one direction. “I think bacteria will grow the most in…”


1. First, prepare your petri dishes. You will need a control, or a dish in which nothing will be swabbed on it to compare the others to, a base point used for comparison. Divide each dish in half by flipping the dish over, drawing a line down the middle. On one side have your child write “C”, on the other, the name of the place being swabbed.

2. Next, decide on the areas you want to swab, kitchen sink, dishwasher, toilet, remote, or cell phone – anything. Label each petri dish accordingly.

3. Carefully open and pull out one cotton swab. Moisten the cotton swab with distilled water.*

4. Swab the dish very carefully by lightly pressing down and gently moving the swab back and forth. If you press too hard you will puncture the agar.

5. Close the dish and secure with tape to prevent accidental opening.

6. Place in a warm area of the home and wait for growth.

* You will want to lessen the amount of variables in your experiment. So, attempt to keep as much constant as possible. Using distilled water means that the water itself shouldn’t have traces of bacteria in it. Have the same person swipe the petri dish and place the petri dishes in the same area to wait for growth. Do not touch the end of the swab with fingers, etc. This way you will know that what you are measuring is collected bacteria from each specific area. However, the younger the child the harder this will be, so attempt to keep things constant but also don’t let it hinder them from learning. 


Have your child keep track of the results after 24 and 48 hours. Draw circles on a paper and illustrate what each dish looks like.


Discuss the results of your experiment. Did they support your hypothesis? Ask more probing questions. “Why do you think bacteria grew more on X? What do we see at X that would make it a good place for bacteria to grow? What did you learn about our home?”

Science can seem scary and overwhelming – but the truth is, science mimics the way children learn naturally by using their own curiosity to explore the world around them. By completing experiments with your child you are simply guiding their learning, while having fun together!

Interested in learning more about getting involved in your child’s learning? Check out Improving Your Child’s Learning through Parental Involvement and an iPad.

Sources: Biology4Kids, EZBioRearch

Photo Credit: Ashley Wells


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