Hands-on Science: What is blood made of?

What is blood made of  A hands-on science demonstration

Blood has become a familiar sight in our household these days.  Whether it is a scraped knee or bloody nose (from intense allergy issues), blood is quite intriguing to our boys.  After one of our recent encounters with blood, Big Brother asked the question, “What is blood made of?”


We checked out some library books on the human body and began our research.  I have used water beads in sensory tubs before and immediately knew the perfect way to demonstrate the various parts of blood in a fun and hands-on way!


*Please note:  This activity is not suitable for children under the age of 3.  Please be careful with younger siblings as the water beads can be a choking hazard.


Here’s what you’ll need:  a large plastic container (or sensory tub), red water beads, ping-pong balls (super cheap on Amazon), water, and red craft foam.  



1.  Follow the instructions on the packaging to hydrate the water beads.  Go ahead and put them (and the water) into your plastic tub / sensory table to soak.  Our package instructions indicated that once you add the water, it takes 10 hours for them to fully hydrate.




2.  Cut the craft foam into small pieces to create your platelets.





3.  Put the “platelets” and several ping pong balls in your plastic tub.







4.  Let your kids explore for a while and then tell them the parts of blood:

Red water beads = Red Blood Cells (that carry oxygen)

Ping Pong Balls = White Blood Cells  (that fight germs, bacteria, and viruses)

Craft Foam Pieces = Platelets (that help heal cuts)

Water = Plasma (helps the blood move through veins and arteries)





This was a huge hit for the boys…and they were able to give Daddy a full synopsis once he came home from work!





From the book:  The Human Body 





From the book:  Body:  An Amazing Tour of Human Anatomy




What is blood made of science demonstration

Overall, a great learning experience for us all!  What is your favorite science experiment?

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  1. Jill says

    This is a great idea! For a fun treat you could reinforce the same concept by making Kool-Aid: cherry crystals (red blood cells), sugar (white blood cells), ice cubes (platelets), and water (plasma.)

  2. says

    I love this very much! I’ve definitely pinned for a future homeschool activity once we get there (and my child is older), but what a fantastic way to teach children about blood! It looks so inviting and not ‘scary’ or ‘icky’!

  3. says

    Thanks for the idea,this is a great idea for my son who is blind. For him everything is hands on a nod this will help me explain blood to him. Thank you!

  4. Martha says

    I am a retired science teacher. I used candy in salad oil. Candy: white jelly beans (white blood cells), red hots (red blood cells), candy sprinkles (platelets). The salad oil is the plasma. Make sure your ratio is reasonably correct.

  5. says

    This is such a wonderful idea. I don’t think *specific* size and ratio matter, this is clearly an activity for little kids… little kids don’t need things to be literal. Especially considering they have images in their science books to refer to :)

    Where can you buy red water beads? Are they sold in stores like Super Target or a specialty store or do I have to order online? I ask because I just read to my kids about blood in our science book and don’t want to wait four days to receive them to do this with my kids, it looks that fun!! ha

    • says

      You should be able to buy them at craft stores (in the floral department), but there is also a link in the post to where I purchased them (on Amazon). :)

  6. Kelly Grisham says

    I created this model for my second graders and also took it to our Math and Science night. The students had so much fun “feeling” the contents of their blood. They will never forget it either! Thanks for sharing :)

  7. Amanda says

    I love this idea for teaching younger children! I’m thinking about doing this for my little preschoolers. Do you know approximately how long it took for the water beads to fill up? I want to have it prepared and ready to go, you know how impatient kids can get.

    • says

      My package says it takes 10 HOURS for the water beads to fully hydrate, so I would definitely do that the evening before so they are ready to go the next day. :)

  8. Patricia says

    Hi there can you tell me how many packages of the beads you used – we have 10g packets and I am not sure how many we need to fill a tub.

    • says

      I didn’t even use an entire packet…just a couple tablespoons. I think you use 1 tablespoon per 10 cups of water, so they expand quite a bit!

  9. Pattie Small says

    Platelets are actually the fragmented bits of a huge cell — maybe instead of little rectangles you could cut circles into little piece

  10. MamaGames says

    Thanks for such a great idea! We made this bin today with two small changes – we couldn’t find cheap ping pong balls, so we used the hollow plastic “practice” golf balls instead ($2 for a dozen) and we cut small discs out of pink foam to be our platelets. My daughter brought down some of her dollhouse dolls so she could recreate scenes from the Magic School Bus! :)

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