How to Make a Potato Powered Calculator

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

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School science fair coming up? Don't worry: We've got step-by-step instructions to dozens of science projects in this Howcast video series, including how to build an erupting volcano, how to make glow-in-the-dark art, how to make a weather barometer, how to make disappearing ink, how to make 3-D glasses, and how to make a marshmallow gun.

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

Steps

1. Step 1

Number potatoes

Label your potatoes one and two.

2. 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.

3. Step 3

Insert nails

Insert a nail into each potato and stick a copper wire into each potato, opposite the nail.

4. Alligator clips, nails, and wire can be purchased at your local hardware store.

5. 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.

6. 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.

7. 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!

8. Did you know? Americans eat 130 pounds of potatoes per person each year.