A coin sits on the table with an empty glass standing on top of it, and everybody can see it through the side. You pour water in and put a saucer over the top. Look through the side now and the coin has gone.
🌟 Level 1: Apprentice
⏱ 2 minutes to learn
🧪 Potions
🎒 Ages 5+
Works by itself, or one simple move. It works the first try.
👶 Small parts! Keep them away from little brothers and sisters, and never put one in your mouth.👶 Coins are a choking risk for little ones under 4: keep them off the floor and out of small hands.🚫 A potion is for looking at, not for drinking.
The thing doesn't really go anywhere. It gets hidden in a hand, a fold of paper, a sleeve or a pocket, or it was never where you thought it was. A magician might pretend to take a coin with one hand while it quietly stays in the other.
Is magic real?
Magic tricks aren't superpowers, and that's what makes them amazing. A magician is a performer who uses skill, science and storytelling to make the impossible look like it just happened in front of you. The wonder you feel is completely real, though.
The Disappearing Coin in Water for kids: the whole trick
A coin sits on the table with an empty glass standing on top of it, and everybody can see it through the side. You pour water in and put a saucer over the top. Look through the side now and the coin has gone. It's a level 1 apprentice trick for ages 5 to 10 (grades K–4th), takes 2 minutes to learn, and needs 4 things you already have. Flick, the shop's rabbit, reads every step aloud with a picture, so a child can follow it alone.
The secret
Light from the coin bends so hard going through the water that it bounces back inside the glass instead of reaching your eyes. The coin is still there; the light just can't get out sideways.
What you need
A clear glass or plastic cup
Water
A coin
A small plate or saucer
How to do it
Put the coin on the table and stand the empty the glass on top of it.
Ask everyone to crouch down and look through the side. There it is.
Fill the glass with the water, right to the top.
Lay the saucer over the mouth of the glass like a little lid.
Look through the side again. The coin has gone.
Lift the saucer off and look straight down to show the coin never moved.
Magic words to say
“This is invisibility water. I keep it in a glass because it's the only thing that can hold it. Anything underneath disappears. Watch the coin.”
Pro tips
Get your audience down to table height before you start. From above it doesn't work at all, and from above is where grown-ups look.
Take the lid off and put it back a couple of times so the coin blinks in and out.
Follow it with the Arrow Flip, which is the same science doing the opposite job.
If something goes wrong
If the coin is still visible, there isn't enough water, or somebody is looking down into the glass. Top it up and ask them to put their chin on the table.
Safety notes
Small parts! Keep them away from little brothers and sisters, and never put one in your mouth.
Coins are a choking risk for little ones under 4: keep them off the floor and out of small hands.
A potion is for looking at, not for drinking.
No fire, no flames and nothing sharp in a child's hand anywhere in the Magic Shop. Nothing ever goes in a mouth, a nose or an ear.
The science behind the trick
This is called total internal reflection. Light slows down and bends when it leaves water, and past a certain angle it can't leave at all: it reflects back down inside the glass. The coin's light reaches the sides and turns straight back, so none of it gets to your eye.
What kind of trick is this?
💨 Vanish. Something disappears. Almost every trick ever invented is one of eight kinds, and knowing which one you're watching is how magicians work out how a new trick is done.
The skill it teaches:Misdirection. People look where you look. Perform it and it counts towards the Kitchen Alchemist badge.
Questions about the disappearing coin in water
How do magicians make things disappear?
The thing doesn't really go anywhere. It gets hidden in a hand, a fold of paper, a sleeve or a pocket, or it was never where you thought it was. A magician might pretend to take a coin with one hand while it quietly stays in the other.
Is magic real?
Magic tricks aren't superpowers, and that's what makes them amazing. A magician is a performer who uses skill, science and storytelling to make the impossible look like it just happened in front of you. The wonder you feel is completely real, though.