This is a great lab activity using food products to simulate the make up of blood. Students receive a real visual of the blood. I used red and white tic tacs for red and white cells or you can use red hots (I could not find those), corn syrup for plasma, colored sprinkles for platelets. You mix them in proportions to the proportions in real blood in a zip lock bag. Students also have a math component as they need to compute ratios of amounts. It is a big hit!