Bath Tub Science For Kids

Easy, fun bath tub science ideas to do with your toddler or preschooler.

Water play is one of the most exciting forms of play for young children. A lot of learning can happen while in the bath tub without any formal lessons being taught. The bathtub is a great place to explore math and science concepts used to develop medicine at and have fun with bathtub science.

Why not make your child’s bath time an ongoing science experiment? When they experiment, they can learn about different properties and volumes of objects. They also understand more about water and how it moves.


Let your child experiment with water by pouring and measuring. Provide different sized measuring cups, measuring spoons, funnels, plastic bottles, pitchers, an eye dropper, and a turkey baster.

Let your child try to predict if pouring water from one container to the next will fill it exactly, overflow it, or not be enough. Count how many tablespoonfuls it takes to fill a measuring cup. Predict how many tablespoonfuls it will take to fill other similar sized objects.

Look for any patterns. Try to always refer to the measuring cups and spoons by their correct measurement name, i.e. ¼ cup or tablespoon.


Gather some everyday objects that can be put into the tub, such as a sponge, a large plastic toy, a small plastic toy, a swimming shoe, a bottle of lotion, a block, a quarter, a paper clip, a cotton ball, a Styrofoam plate, a spoon, and a rock. Try to find different sized and weighted objects. You can also use some of the new magnetic toys, Check the review of magnetic toys by TechyChoice here. Ask your child if she thinks each individual object will sink or float. Have your child explain why she thinks this will be the case. Let her drop the object into the tub. Did her prediction come true?

Let your child tell you possible reasons why. Typically, children believe that large objects sink and small objects float. Try another object. Discuss her findings and conclusions.


Fill each egg hole of a white Styrofoam egg carton 3/4 full of water. Add red food coloring to one section, blue to another section, and yellow to another section. Give your child an eye dropper.

Show her how to use the eye dropper to move the colored water to the clear water sections. Notice how the color changes. Let her experiment. Have her mix colors. Can she make green or orange?

Make colored ice cubes by adding a drop of food coloring to the water before freezing. Toss them into the bath tub and watch them melt. Why do they melt? What happens to the color? Mix colors.

You can also play with color by squirting shaving cream into a muffin tin and then adding a drop or two of food coloring to each squirt. Mix the colors with your finger to blend. Let your child “body paint” with the shaving cream. Be careful to keep it away from your child’s eyes.


Young children love this “magic” trick! Have your child crumple a piece of paper and push it to the bottom of the plastic cup. Next, have her turn the glass upside-down. Make sure that the paper remains stuck up in the cup.

Have her keep the cup perfectly straight up and down (vertical position) and push it through the water until it touches the bottom of the tub. If she’s kept it perfectly straight, the air trapped inside the glass will prevent the tissue from getting wet. Wow!


The day before your bath experiment time, mix together water, dish soap and glycerin. I’ve heard that sugar will work as well as glycerin but have never tried it. Leave it alone until bath time. The longer bubble juice sits the better the bubbles will last, also getting the best bath toys for kids which is a great option for kids to enjoy the bath.

Pour the bubble juice into a loaf pan and give your child different objects to try to blow bubbles through, i.e. slotted spoon, water bottle sport cap, a straw, a small funnel, cookie cutter.

Experiment with different objects and see which work better and discuss why this may be so. What happens to the bubbles when they land on something dry? What about on something wet? Can you catch the bubbles? Can you stack the bubbles?

Have fun and learn without your child even noticing it!

Jennifer Ellis is a former elementary teacher and is now a stay-at- home mom.

Like this article? Check out my 13 bath time activities for toddlers and how to make bathtub paint.

Follow my preschool activities board on Pinterest.

Easy, fun bath tub science ideas to do with your toddler or preschooler.


1 Comment on "Bath Tub Science For Kids"

  1. As a retired educator, and grandparent of boys—ages 6 & 4, I applaud (and immensely appreciate) your post! My husband (retired US Air Force–educator, as well) and I appreciate the resources and advice of people who are much more qualified than we to lovingly challenge our boys with science, math, the arts, etc. in their elementary years. In other words, we feel you’re doing terrific, constructive things in your sabbatical or retirement! We also commend you for your choice to stay at home with your kiddos. Creative people, like you, sometimes find this a difficult decision to make. The experience of two soon-to-be 62 year olds tells us you will be rewarded for your decision…over and over and over during the developmental changes in your kids’ lives. THANKS for the help you’ve given us!

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