Each group needs:

• glue stick
• roll of transparent tape
• ruler

For the class to share (to be "purchased" by each group):

• printer or copier paper (can be recycled)
• construction/craft paper (stiffer than printer paper)
• index cards

For teachers use only:

• 12-inch length of fishing line or other nylon/strong string
• 1-2 foam/paper cup (only one is needed, but have a back-up)
• variety of incremental weights (between 5 g - 20 g)
• digital scale (with a resolution of 1g)
• (optional) LEGO MINDSTORMS EV3 ultrasonic sensor. Note: This activity can also be conducted with the older LEGO MINDSTORMS NXT set. 
• (optional) access to computer with Microsoft Excel®