We've been learning a lot about the heart along with arteries, veins, and capillaries. So we took the time to make some blood that the girls will never forget. Here are the instructions: 1. Fill a jar with water, you could put in a little yellow food coloring to make it look like plasma. 2. Take some cheerios and put them in a zip lock back and shake them around with red food coloring. This makes the red blood cells. 3. Pour the red blood cells, white blood cells (white marshmallows), and platelets (purple pom poms) in to the jar. Then you have something interesting to look at.