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How to Make a Potato Powered Calculator

Long a science-fair project staple, this potato powered calculator is easy to recreate yourself!


  • Step 1: Number potatoes Label your potatoes one and two.
  • Step 2: Remove battery Remove the batteries from the calculator. Take care to note where the positive and negative terminals are within the battery compartment.
  • Step 3: Insert nails Insert a nail into each potato and stick a copper wire into each potato, opposite the nail.
  • TIP: Alligator clips, nails, and wire can be purchased at your local hardware store.
  • Step 4: Connect clips Connect one alligator clip to the copper wire in potato no. 1 and attach the other end to the positive battery terminal in the calculator's compartment.
  • Step 5: Create second connection Clip a second alligator clip to the nail in potato no. 2, and then connect the other end to the calculator's negative battery connection.
  • Step 6: Complete circuit Complete the circuit by clipping the third alligator clip to the nail in potato one and to the copper wire in potato two. Voila, a working calculator!
  • FACT: Did you know? Americans eat 130 pounds of potatoes per person each year.

You Will Need

  • Two potatoes
  • A marker
  • Two pieces of heavy copper wire
  • Two galvanized nails
  • Three alligator clips with wires
  • A low-voltage
  • battery-operated calculator

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