Here is an easy and fun science experiment.
Find some cereal that has iron in it. We used Rice Chex, because it is gluten free and has 50% of your daily iron. I have heard Total is a good one, because it has more iron in it.
Dump some cereal in the blender with some water, and mix it until it is a nice thin mixture. We did not measure the amounts. Just make sure that the mixture is thin. (I also read that some people just soak the cereal in water for a couple hours.)
Place the mixture in a bag with a good seal, and keep some air in the bag. Then place a strong magnet next to the bag and swirl the liquid around slowly.
Move the bag so that the mixture is not touching the bag near the magnet.
What is that black stuff?
Well it sticks to the magnet, so it must be iron. Yes your cereal really does have metal in it.
Alternatively, you can find some thin plastic and pour the cereal slowly across it while holding the magnet underneath the plastic.
Then my kids had fun using the magnet to play with the iron particles. They kept moving the iron around with the magnet and making into rings. (Let your kids have fun playing with science, they often discover things through play that were not even part of the intended lesson.)
Now that your kids know that they eat iron every morning, they can run around the house singing, “I am Iron Man”.