Each group needs:

• 1 sheet of paper and a pencil or pen
• 1 pair of scissors
• 1 model heart, a cardboard box with a divider in the middle (see Figure 1)
• 30 marbles (representing blood cells)
• Valve Replacement Project Worksheet, one per group

To create a model heart box, one per group (made in advance by the teacher; see Figure 1):

• 1 box, size can vary, for example, use old banker's storage boxes or copy paper boxes, approximately 10 high x 12 wide x 15-inches deep (25 x 30 x 38 cm), no lid needed
• divider wall made from cardboard (cut from lid or flaps) and packing tape
• scissors or box cutter, to cut cardboard and tape
• (optional) marker, to identify heart chamber names
• (optional) red spray paint

To share with the entire class:

• tissue paper, 1 pack
• construction paper, 1 pack
• cardboard, scrap pieces, about 1 per group
• brown paper bags, available at grocery stores
• Popsicle sticks, available at hardware and hobby stores
• index cards, 1 pack
• wooden toothpicks, one box
• string, 1 roll (~280 ft or ~85 m)
• aluminum foil, 1 box
• duct tape, 3 rolls
• scotch tape, 5-10 rolls