How to use mathematical principles to read minds (guess numbers) in three ways?

Directory method 1: get the answer 3 1, and ask your friend to choose a number between 1 and 10. 2. Multiply the selected number by 2. 3. Multiply the answer by 5. 4. Divide the answer by the number selected at 1 time. 5. Subtract 7 from the obtained figure. 6. "Guess" the answer. Method 2: Make 1 more complicated, and let friends choose a number between 1 and 10. Multiply this number by 2. 3. Choose your own number (it is better to choose an even number, which is more convenient to operate). 4. Divide the answer by 2. 5. Subtract the number selected at 1 time. 6. "Guess" the answer. Method 3: Get the answer 13 1, and ask your friends to choose a number between 1 and 10. 2. Multiply the selected number by 9. 3. If it is two digits, add up the figures. 4. Add 4 to the answer. The final number will be 13. As long as you remember the following steps, you don't need to be too smart. You can make your friends think that you know "mind reading" just by numbers.

Method 1: get the answer 3.

1, let friends choose a number between 1 and 10.

2. Multiply the selected number by 2.

3. Multiply the answer by 5.

4. Divide the answer by the number selected at 1 time. For example, if they choose 3 in step 1, they should divide the current number, that is, 30 by 3.

5. Subtract 7 from the obtained figure.

6. "Guess" the answer. As long as the steps are correct, the answer is always 3!

Method 2: Make it more complicated.

1, let friends choose a number between 1 and 10.

Multiply this number by 2.

3. Choose your own number (it is better to choose an even number, which is more convenient to operate). Ask a friend to add this number to the current number in his heart.

4. Divide the answer by 2.

5. Subtract the number selected at 1 time.

6. "Guess" the answer. As long as the steps are correct, the answer should be half the number you gave them in step 3.

Method 3: Get the answer 13.

1, let friends choose a number between 1 and 10.

2. Multiply the selected number by 9.

3. If it is two digits, add up the figures. Single digits (such as 9), and then add 0.

4. Add 4 to the answer.

The final number will be 13.

Tip: familiarize yourself with these steps before you start reading minds.

Before proceeding to Step 3 of Method 2, think of a number in your mind.

Give them some time. Mental arithmetic is not easy, especially for children. If you can, give them a calculator.

In step 4 of method 1, the answer will always be 10. If you play tricks on many people at the same time, you can change the numbers in step 5. Just subtract the number in step 5 from 10, and you can work out the final answer.

In the fourth step of Method 3, you can ask them to add or subtract any number at will. Just remember, add and subtract 9 from the number you told them, and you can work out the final answer.

Warning: If there are two or more colleagues at the same time, these methods will not work.