Here is a Card Trick you can do holding the cards, OR, handing over the cards to the other person and follow your instructions and you will always get the correct card to show up... now, it is like "Memory" ... this is the enticing thing. So, to perform this, you need a standard deck of cards (52) ... so this is what you want them to do, or you are going to tell them what you are going to do.
"I am going to count out 26 cards face up [after shuffling] in a pile and prove I have a great memory."
... note: so you count out 26 cards face up in a pile (on top of each other) without pause with them.
... take that pile and turn it face down and place it under the other stack (basically put the other 26 cards on top)
Flip over the top card... [what ever shows, you ensure it adds up to 10].
... Ace appears... [one + what makes 10?]
... 9 they say, [so place 9 cards FACE DOWN under the ACE]
... now flip over the next card.
... Jack appears... [10 + what makes 10?]
... 0, so you can flip the next card then
... 7 appears ... [7 + what makes 10?]
... 3 they say [so place 3 cards face down under the 7]
... Add up the numbers of the 3 cards faced up.
... Ace = 1, + Jack = 11 and 7 = 18... this is the total.
Okay... count 17 cards from the top of the deck FACE DOWN, leaving the 18th card, and that card will be... (the card you remembered from the first 26 cards counted at the start) ... also note, even if the other person is holding the deck and following your instructions, YOU will still get the right answer.
I am sure you can figure it out from here.
Hehe good one, its kinda somewhat the same function as the 9 multiplication one.
1. Ask them to type a secret 4 digit random number.
Lets say he pick 3573.
2. Tell him to subtract that number in opposite direction on a calculator.
3573-3753=-180 (we have a zero here, gives a 50/50 between 0 and 9.
3. Then tell him to say all but one of the digits.
Lets say he say 1 and 0.
9-(1+0) = 8, so you know the last digit is 8.
If he gave you the digits 1 and 8, well then you are in a 50/50 scenario.
Because 18-(1+8) = 9, meanwhile 9-9 = 0. And you do not know which.
So you have to be clever with the question here, or say its either 9 or 0.
The same way you can multiply any digit with 9, and ask them to tell you all but 1 digit.
479*9=4311
9-(3+1+1)=4
9-(4+3+1)=1
9-(4+1+1)=3
If the number of the 3 given digits sum up to over 9 you have to subtract from 18.
You can also ask him to give you only 2 numbers and you know the 2 next ones:
Lets say he gives you the 4 and 3.
Next in the 9 multiplication is 9x5=45
45-43=2, only possible combination is 1+1, so you know the last 2 digits.
You need to know number of digits, which is why you ask him to say all but 2…
Edit:
In the card trick, what if the flipped card is queen or king? Aka 11 or 12?
Is it then what makes 20?
This post was edited by gel87 on Oct 30 2025 04:33am
D2:R