Blood (Circulatory System)
No one was willing to sacrifice a sampler of their blood to centrifuge for this project, so we resorted to model-making. Blood is composed of 55% plasma (hormones, nutrients, electrolytes), 40% red blood cells (deliver oxygen to tissues) and the last % is devoted to white blood cells (fight infection) and platelets (cause clotting). We used corn syrup to represent plasma, red goji berries to represent red blood cells, navy beans to represent white blood cells and rice grains to represent platelets.
https://www.123homeschool4me.com/blood-for-kids-actiivty-to-learn-about-the-human-body/
jOnce we had created a visual model, we sketched a test tube version to show percentages. The big kids used the typewriter to label their work.
Then we took a look at Operation Ouch https://www.youtube.com/watch?v=tqsuu9DiJWQ to get their version of how blood is essential to the human body.