Focus is always good. Especially math ones. They can not only entertain the company, but also give the audience the impression that they are faced with Perelman himself or Einstein.
Birthday
Suppose you suddenly needed to impress your interlocutor (tsu) with your combinatorial abilities, and you left the board dotted with calculations at home. There is a way - guess a person's birthday without a calculator and looking at his page on a social network.
Invite the interlocutor (tse) to multiply the date of birth by three. Then ask them to divide the resulting number by nine. Not every number is divisible by nine without a remainder, therefore, most likely, the resulting number will consist of a quotient and a remainder. Bring this simple but necessary maxim to the interlocutor (tsy). Let him (she) multiply the quotient by three, and divide the remainder by three. Then just add up the numbers. Everything. You can name a number.
For clarity. Suppose you were born on the 8th.
1) 8*3=24
2) 24:9=2 (6)
3) 2*3=6
4) 6:3=2
5) 6+2= 8
How many years?
This mathematical trick is best shown to men. Age is a delicate matter. So, ask a friend to multiply his age by five. Let him add eight to the amount received, and multiply the result by two. You need to subtract six from this number, and multiply the resulting amount by 10. You subtract 100 from the result and divide by 100. Before you - the age of the interlocutor.
For clarity. Suppose you are 20 years old.
1) 20*5=100
2) 100+8+108
3) 108*2=216
4) 216-6=210
5) 210*10=2100
6) 2100-100=2000
7) 2000:100=20
two digit number
Guessing numbers is interesting in that the person to whom you propose to participate in a mathematical attraction will try to guess the number "more difficult", although mathematics does not know such concepts. There is an algorithm - it will help you in the "magic".
Let your friend think of any two-digit number. Then he will divide it into three, into five and into seven, and he will tell you the remainder of each division. You can easily guess the number. How? Now let's explain.
Multiply the remainder of a division by three by seventy, multiply the remainder of a division by five by twenty-one, and multiply the remainder of a division by seven by fifteen. The resulting numbers must be added and divided by 105. That's it. The remainder obtained by division is the age.
For clarity. Suppose the intended number is 25.
1) 25:3=8 (1)
2) 25:5=5 (0)
3) 25:7=3 (4)
4) 1*70=70
5) 0*21=0
6) 4*15=60
7) 60+70=130
8) 130:105=1(25)
Multidigit addition trick
Adding numbers is one of the simplest operations, especially if the numbers are single digits. But when you need to add multi-digit numbers, things get more complicated. Only not for you, because you know the mathematical "magic".
So, ask the person with whom you decide to compete in counting speed to write several numbers with the same number of characters. The bigger, the better. Then add your own to this long series of numbers. Then offer to add up all the numbers for speed. To win this competition, you need to know the secret.
Here it is: the numbers you write should consist of numbers such that each of them complements the numbers in your opponent's numbers up to nine. If the number of written numbers is x, and the number of digits of each number is y, then we find the required amount using the formula x*(10 y - 1). If one of the numbers consists of only nines, then there is no need to add an additional number to it.
Imagine yourself as an illusionist and surprise your guests with simple but fascinating magic tricks. Attention! The magic begins.
"Rhino in Denmark" - a trick with a trick, and for the magician himself
The puzzle is based on a number game.
Properly choose an assistant: the level of intelligence is more important than the size of the bust. Invite her to complete some simple tasks: choose any number from 1 to 10. Speak in a mysterious voice. Multiply it by 9. If the resulting number consists of two digits, add them. On the first letter of the number, guess a country in Europe. Think of an animal for the third letter of the name (a paradox, but it will be a rhinoceros!). Looking closely into the eyes of the assistant ... ask: “Where are the rhinos in Denmark from ?!”
Focus "Magic in an envelope"
You will need a sheet of paper, a pen, an envelope. Write on a piece of paper a four-digit number that is twice the number of the current year (for example, if it is 2009, then the number should be 4016). Put the sheet in the envelope, and leave the envelope itself in plain sight. Do everything slowly to create an atmosphere of mystery. Choose the girl you are interested in and ask her to write on another sheet of paper the year of her birth, the year of an important event in her life (for example, the first kiss), the number of years that have passed since that moment, her full age. This sheet contains strategically important information for you! The secret is that although all four numbers important to her seem completely random, they always add up to the same thing. Girls are the main "props" of holiday tricks.After the girl writes all the numbers, let them sum them up. Do not forget to offer your help in the calculations, she will be grateful to you. By the way, the magician's costume will have a special effect on the audience. Ask the assistant to open the envelope and read the number on the paper. As if by magic, the amount she calculated will equal the number you entered! The secret of the magician's magic is surprise.
Focus "Seer"
You will need 11 sheets of paper, a pen, a hat (or other container). Invite more beautiful girls to participate in your trick. Let them name 10 celebrities for you, no restrictions, they can be singers, actors, and scientists. Take 10 sheets of paper and write down the suggested names for each. Choose one of the sounded names and write it on all the sheets.
Fold the papers in half and place in the hat.Now write your chosen name on a separate piece of paper and put it in an envelope. When comparing names on sheets - voila! Everything will match!
Focus "Literary Evening"
You will need a sheet of paper, any book, an envelope, a pen, two dice. Take a book, preferably thicker, for example, Pushkin's volume, open page 14 and copy the first word from it onto a piece of paper. Then put the piece of paper in the envelope and put it in a conspicuous place. After simple preparations, look around and choose your assistant. After giving her some compliment, ask her to roll two dice. Now have them add the top and bottom numbers on each die. Then, with a mysterious look, give the assistant a book and ask her to read the first word on the page, the number of which is the amount received. The secret is that the sum of the numbers on the top and bottom faces of the cubes is always equal to 14. Finally, wink at the assistant - let her open the envelope and read the word on the sheet aloud. Bravo! The words matched. Just before the trick, do not forget to ask the charming assistant about the profession of her husband, all of a sudden he turns out to be a real magician, then beware.
