Growing a potato in water is a relatively simple science experiment that involves submersing part of the potato in water and exposing to sunlight. The project lasts for approximately three weeks, and once finished, the potato can be planted soil to grow to maturity.
Before submersing the potato in water, insert tooth picks into the potato approximately 2/3 the way up from the end that has the most sprouts. Then, place the sprouted end into a glass with the toothpicks resting on the rim of the glass. Add water to the glass so that the potato is half underwater, and then place it on a window sill or another area with ample sunlight. Sunlight evaporates water, so check the potato periodically to ensure proper water levels.
After two to three weeks, the potato begins to grow roots in the water. Shortly thereafter, it sprouts its first leaves. The top of the potato usually cracks open to allow the shoots of the new potato plant to sprout. Leave the plant in the glass until it sprouts its first leaves, and then transfer it into a pot or plant it directly in the earth.
During the entire process, document the changes that occur in the potato, even taking photos. Compile the notes and photos and submit.