This lab is a great way to give students hands on practice with separating mixtures. They will also love sing how there are actually "chuncks" of iron in our cereal that we can pull out with a magnet.
The first part can be done a few different ways. It is dissolving salt into water and then making the water evaporate and to see what is left (the salt is too heavy to evaporate so you can separate the salt from the salt water) If you have a window sill students can set their cup near the window (just make sure they use a very small amount of water...possibly even smaller than what is suggested on the sheet) or you can add heat to the mixture if you have hot pads at your school and boil the water away and see that salt is left over.
The second part requires cereal (high in iron) and magnets. Students will have to crush the cereal into fine power. then put a magnet up next to the smashed cereal and see if you can get iron to stick to it. (I've also seen this done where you put the crushed cereal into water so that it's floating and then you run the magnet close to the outside of the bottle and try to attract the floating chunks of iron) Which ever way works for you class is fine.