ENIMAGIC

Effects: You may calculate the square root 5
,very quickly , with numbers randomly selected by the volunteers.

Preparation: Memorize the relationship between First digit number (the left) with the numbers on the right in the following table:
======================
First digit | NUMBERS
======================
1 | 100 THOUSAND
2 | 3 million
3 | 24 million
4 | 100 million
5 | 300 million
6 | 777 million
7 | 1.5 billion
8 | 3 billion
9 | 6 billion


Procedure:

1. Call a spectator up on stage, give him a calculator. Tell them that you will find the square root of 5 with 2 digit numbers very quickly, without the help of a calculator.

2. Have the volunteer choose 2 digit number from 10 to 100, without being noticed by you. (Example 38)

3. Ask him counting the number of rank 5. In this case, 38 x 38 x 38 x 38 x 38 = 79,235,168

4. Ask him to mention the number of points on your number 3.

To calculate the square root quickly 5:

The first digit:

1. See results in point number three, consider the number of positions in which she mentioned in accordance with the table that you memorize the above. In this example, 79235168 between 24 million and 100 million. Means located between the table "first digit" number 3 and 4. The first digit is always shown by the smaller number (in this case 3, because 3 is smaller than 4)

The first digit: 3


The second digit:

The second digit is the last figure mentioned by the volunteers. In this example, 79,235,168. The last number mentioned is 8.

The second digit: 8


Basic numbers of volunteers selected in this example:

The first digit: 3

The second digit: 8

Thus, the baseline (5 square root of the number mentioned volunteers) = 38


Variation: If you are proficient, you can invite some volunteers at the same time, race and race with other volunteers who use a calculator to find the root end 5.

courtesy:
arthur benjamin-inventor of lightning calculator ..!!