one of the great classics, and still as miraculous as ever
The effect
1. A pair of bowls, each about five inches in diameter, are upside-down on the magician’s table.
2. He picks one up, shows it’s empty.
3. Fills it to the brim with Rice.
4. and covers it with the second bowl.
5. When he separates the Bowl rice has doubled.
6. The magician levels off the excess rice.
to prepare
Chinese Rice Bowls are standard magic-shop items, but you can make your own easily enough. Obtain a matched pair of plastic or ceramic bowls about five or six inches in diameter (proportionately smaller if you have small hands). Japanese rice bowls are ideal
Rub the mouth of the bowls over a sheet of 120-grit emery cloth until the rims have been sanded flat.
Lay one of the bowls over a sheet of clear, fairly flexible plastic about 3/64ths of an inch thick, and carefully trace the outline of the bowl with a sharp awl or heavy needle. Cut out the disc with a pair of heavy scissors, allowing a small tab to protrude.
Cut a cardboard or thin, opaque plastic square exactly as wide as the diameter of the disc plus the tab.
Rub a thin coating of Vaseline over the rim of one bowl (bowl A) and fill it almost to the rim with water. Place the plastic disc over the mouth and press it down firmly to force out as much air as possible. You should be able to pick up bowl A and turn it upside-down without spilling a drop.
Scatter a few matchsticks on your tabletop and place bowl A disc-down and tab towards the back, on top of them. (The matches or anything similar keep the disc from sticking to your tabletop.)
Place bowl B mouth-down over bowl A.
to perform
Pick up bowl B, show it to your audience, and fill it nearly to the brim with uncooked rice.
Place bowl A disc-down on top of bowl B, tab towards you, being careful not to show its interior.
Hold the bowls together, thumbs on top, fingers underneath, as you commune with the magic spirits by slowly moving the bowls through the air, finally turning them over so that bowl B is on top.
Remove bowl B. A is seen to be overflowing with rice. (Unless it doesn’t matter if the floor gets messed up, work over your table, or better still, over a tray on your table.)
Set bowl B on your table, and with bowl A in your left hand, pick up the card with your right and use it to smooth the rice level with the rim.
Leave the card on bowl A and place bowl B mouth-down on top of it.
Holding both bowls in the left hand, fingers underneath and thumb on top, place right thumb on the underside of the disc tab and your right fingertips on top of card, carefully slide both out together, and place on your table, disc side down. (This move is tricky and takes practice to perform smoothly.) 
If your hands aren’t large enough to manage, you can remove the card and disc while the bowls are on your table
Again describe a circle in the air with the bowls (but gently, or the water may spurt out). Without turning the bowls over, lift B off A and pour the water from bowl to bowl!
Ph.D. researcher at Friedrich-Schiller University Jena, Germany. I’m a physicist specializing in computational material science. I write efficient codes for simulating light-matter interactions at atomic scales. I like to develop Physics, DFT, and Machine Learning related apps and software from time to time. Can code in most of the popular languages. I like to share my knowledge in Physics and applications using this Blog and a YouTube channel.