Materials Needed:

1 clean 1-liter water bottle with a magnetic wand attached (for each center or group of students).
The wands may be ordered from Educational Innovations:  www.teachersource.com   The order number is #M-510 currently (2005-2006) $1.50 each.  Tie one wand to each bottle's neck with a string or piece of yarn.  (The magnetic wands work better and are easier to use than other types of magnets.)
Collections of the following items:

• Various items made of iron or containing iron such as:  nails, twist tie, battery, wire, paper clip, magnetic marble
• Various metal items not made of iron or containing iron such as:  dime, penny, screw, nickel, Pop-can tab, aluminum
• Various items not containing metal such as:  beads, rubber band, crayon, eraser
• If magnetic marbles are used be sure that there is only one per bottle because two tend to cling together; also be aware that these marbles look a lot like bubble gum – a possible safety issue
• Data Sheet:  1 per student    

Put 4-5 items from the suggestions above in each bottle.  To keep students from removing the cap and taking out the items, glue the cap back on the bottle.  Then tie on the magnet.  For ease of distribution and data collection, consider numbering the bottles.