This fun STEM activity will focus on how much blood a healthy body contains and how donated blood can make someone who needs more blood feel better.

Blood donations are so important for hospitals and patients. Did you know that one blood donation can save up to three lives? This is because 1 blood donation can be separated into 3 parts (red blood cells, plasma, and platelets). These 3 parts can each save a life!

After someone gives blood the body reproduces the blood that was given within 24 hours.

In this activity, we will pretend that someone was in an accident and needs donated blood to feel better. The three bowls will represent blood in a healthy body, a blood donation, and a patient’s body that needs blood after an accident.


  • 2 large bowls (at least 1.5 gallons/ 5.5 liters)
  • 1 medium bowl
  • Paper
  • Writing tool
  • Water
  • 1 Cup or Pint measuring tool
  • Red food coloring (optional)

  1. Using your measuring tool, pour 10 pints (or 20 cups) of tap water into the 1st large bowl. Label the bowl “Healthy Body.” The water represents the amount of blood in a healthy adult body. If you want to make the water look like blood, add a few drops of red food coloring to the water.
  2. Measure 1 pint (2 cups) of water out of the “Healthy Body” and pour it into the Medium size bowl. Label this ” Blood Donation.”
  3. Now take the “Blood donation” and scoop/pour it into the “Patient’s Body”. This represents the amount of blood drawn/taken from the donor and given to the patient. As you can see, the “Patient” needs about 2 more pints (4 cups) or 2 more donations from other people to make them whole.

Now that we understand how blood donations save lives, what can you do to help your community and local hospital?


-Make a Donation Blood Flyer!

-Search for local blood drive near you!