Want to see your money grow? Put a coin in the bottom center of an empty drinking glass. Put about an inch (2.5 centimeters) of water into the glass, making sure the coin stays in position. Look at the glass from an angle slightly above the water level. When you find just the right angle, you will see the coins—appearing to float! And on the bottom of the glass you’ll see a larger coin!

Light rays reflect upward from the coin and bend toward your eye, making the coin appear to float. Also, the curved glass acts as a magnifying lens to make the real coin on the bottom look larger than it is.