Today we're going to build a small windmill, just like the big one on Grandpa's farm. First, gather some simple materials like a wooden stick, paper or thin cardboard for the blades, tape, and a pin or small nail.

Start by cutting the paper into four equal triangle shapes. These will be the blades. Attach each blade to the wooden stick by taping the wide edge of the triangle around the stick, spacing them evenly. Make sure the blades are loose enough to catch the wind.

Next, poke the pin through the center where all the blades meet. Carefully fix this onto a base, like a small box or cup, so the blades can spin freely when the wind blows. Try blowing on the blades or go outside to test if they turn.

If it doesn’t spin well, ask yourself, “Are the blades balanced? Is the pin too tight?” Adjust the blades or the pin position until it spins easily. This simple windmill shows how moving air can create energy, just like the big windmills on the farm.