Blood

Yesterday, I taught three-year-olds about blood. It was my turn to host our weekly home(pre)school group and the theme this month is The Human Body. Our group has an emergent curriculum, meaning we design the curriculum on what emerges from our children. My blood lesson emerged from my three-year-old wanting to know why I told her not to pick her scabs.

We started the lesson with a song. My husband played guitar and sang a really simple song I wrote and set to the tune of "The Wheels on the Bus." (My husband also figured out that it worked to the tune of '90s one-hit-wonders 4 Non Blondes' "What's Up.") I didn't make up hand motions, but if you want to use it and you come up with some, all the better!

The heart is a muscle for pumping blood
Pumping blood
Pumping blood
The heart is a muscle for pumping blood
All around my body

The red blood cells carry oxygen
Oxygen
Oxygen
The red blood cells carry oxygen
All around my body

The white blood eat the germs
Eat the germs
Eat the germs
The white blood cells eat the germs
All around my body

Platelets help my owies heal
Owies heal
Owies heal
Platelets help my owies heal
All around my body

Then I read the book A Drop of Blood by Paul Showers. The book is a little advanced for three-year-olds, but I stopped after each page to give the kids a task. (I love this book. It stars Dracula and Igor and the illustrations are fantastic.)

After the first page, we stopped to measure how many cups of blood we have in our bodies. The estimates I found varied, so I averaged our number at 1 cup of blood for every 7.5 pounds. This means that a 30 pound preschooler has (approximately) 4 cups of blood. The kids loved helping pour water into the measuring cup, pouring water from the cup into a bowl, and then passing the bowl around to feel how heavy their "blood" was.

After the second page, we started our blood model...

Blood Model Recipe

Corn syrup - plasma

Red Hots - red blood cells

Mini-marshmallows - white blood cells

Rainbow sprinkles - platelets

I had every child pour in a bit of each ingredient. For red blood cells and platelets, I gave each child a small handful of Red Hots and sprinkles, but for white blood cells, each child only got one mini-marshmallow to put into our "blood."

I wasn't going for accuracy, but if you're curious...
According to Hematology.org, blood is 55% plasma, 40% to 45% red blood cells, 1% white blood cells, and platelets (fragments of cells).

After the book, we painted people cookies with icing veins and arteries. (Veins are not really blue. This is just the color that diagrams use to show the difference between deoxygenated venous blood and oxygenated arterial blood. Arteries and away start with the same letter; this is how I was taught in high school to remember that blood flows away from the heart in arteries. For an explanation on why veins look blue when you look at your wrist, check out this.) We did use blue and red icing, but we talked about how blood is really just red.

Finally, we painted circulatory system paper bag vests. (Thank you Mom for creating the circulatory system graphic. It's under all that paint somewhere.)...

Who knew blood could be so fun?