This Makey Makey two team buzzer system is made with inexpensive materials so that every classroom can have a quiz bowl style buzzer system. It displays for the teacher which student buzzes in first, and locks out the other students. It also uses conductive bracelets for half of the circuit, so students have a hand free to work math problems or take notes.

Supplies

Makey Makey Basic
Speaker wire (15 feet) -- other thin wire can be used; total needed 10 pieces, each 3 feet
Wires with alligator clips (8)
Rubber bracelets (8) -- other flexible and sturdy bands can be used
velcro (6 inches)
connector wires (4) from Makey Makey basic
corrugated cardboard
tape
paper or cardstock
aluminum foil
Scratch program https://scratch.mit.edu/projects/418038700/

Step 1: Buzzer Pads

Cut pieces of corrugated cardboard for the buzzer back. I cut 3" x 3" squares with a tab on the top for the alligator clip.
Cover the front of the cardboard with aluminum foil and tape it on the back. Make sure the tab is covered completely and securely.
Cut pieces of paper or cardstock for the front of the buzzer. Cut a hole in the middle of each for the buzzer 'button'. Label each with the team (Team A or B) and student number (1 - 4).
Wrap the edges of each buzzer with tape - this keeps them from buzzing if they accidentally touch.

Step 2: Earth Bar Bracelets

Cut speaker wire into 3 ft lengths (you will need 5), and separate each into two separate strands.
Cut each rubber bracelet to open into a flat strand.
Cut 8 strips of aluminum foil approximately 3.5 inches wide and the length of the bracelet.
Wrap aluminum foil around the bracelet until almost completely wrapped.
Cut a slit in the middle of the foil where the wire will be inserted.
Strip the end 3/4" of the wire.
Lay the stripped end on the foil wrapped bracelet at the cut slit.
Wrap the aluminum foil over the wire and tape.
Wrap and tape the other side of the bracelet and put another wrap of tape over the protruding wire to hold it securely and keep it from being pulled out.
Affix velcro to the two ends of the bracelet.

Step 3: Team Earth Bars

Each team's bracelets are attached to a separate Earth bar. These are then attached to the Makey Makey with a 3 foot connection. This gives the students more flexibility of movement without tugging on the Makey Connections.

For each Earth bar (you need 2):

Cut a piece of cardboard 2" x 5".
Cover the cardboard with aluminum foil.
Strip the ends of the wires connected to four of the bracelets.
Tape the wires to the Earth bar.
Strip 3/4" off the end of one of the unused 3 foot pieces of speaker wire (this will be the wire that attaches to Makey Makey).
Tape the wire to the Earth bar, coming off the other end.
Put an additional piece of tape over the length of the bar to hold all the wires securely.

Step 4: Connect to Makey Makey and Play!

Connect the buzzer pads to Makey Makey using the alligator clip wires:

Team A, Player 1 - attach to 'a' (on the back of Makey). Use a connector wire in Makey then attach the alligator clip to the connector wire.
Team A, Player 2 - attach to 's'.
Team A, Player 3 - attach to 'd'.
Team A, Player 4 - attach to 'f'.
Team B, Player 1 - Attach to left arrow
Team B, Player 2 - Attach to up arrow
Team B, Player 3 - Attach to down arrow
Team B, Player 4 - Attach to right arrow

Connect both Earth bar wires to the Earth bar connection on Makey. Tape the Earth bar to the table in front of the students on that team.

Run the Scratch program: https://scratch.mit.edu/projects/418038700/

Enjoy!