To introduce your students to the scientific method, design magnetism activities with an investigative angle. One winning activity is to provide students with large buckets of assorted household items, both magnetic and non-magnetic. For example, you can include paper clips, hair clips, refrigerator magnets, and screws, as well as various plastic or paper items. Have the students hypothesize about what items their magnets will attract and then test their hypothesis. For a game-like activity, let students work in groups to "fish," using magnets at the ends of strings to fish for paper fish spread on the ground, each clipped with a large or small paperclip. Have students compare the relative strength of large or small paperclips or various magnets.
Whatever magnet activity you select, you can add interest for your first-graders by using colorful or decorative magnets. Buy a set of magnetic letters for a fun variation on the "go fish" activity; after each group of students fishes for a set number of letters, they have to try to form their catch into a word or words. Alternately, get students excited about the project by assigning each of them to bring in one magnet from their home or refrigerator. Have some spare fun magnets on hand in case any students do not have access to magnets at home.
At the first-grade level, your magnetism project can focus simply on the properties of attraction and repulsion found in magnetic items. They can discern between items that can and cannot hold a magnetic charge. As an extension, you can introduce them to the possibility of inducing or removing a magnetic charge. Show the students how to magnetize a nail by running a strong bar magnet along its length repeatedly. Let them hypothesize about the number of passes necessary for creating magnetism in the nail, then experiment to find out how close they came.
Once your students have learned the basics of magnetism, let them apply the principles to creative games. Have each student design a maze on a piece of paper, with the passageways of the maze just large enough for a paperclip to pass. Have each student magnetize a paperclip to use as the game piece. Students can then swap mazes and try to guide the paperclips with magnets, held directly underneath the table, with the maze taped to the table so it won't slide. Check that your classroom desks or tables are sufficiently thin before launching the activity. If not, you can extemporize with a sheet of poster board, and more children can participate in each game by helping to hold it up.