math magician trick
Math Magician Trick
Select a number from 1 to 70
Divide it by 7. (Use a calculator. You’ll need one that has at least seven decimal places.)
If your total is a whole number divide the answer by 7 again.
Check is there a 1 somewhere after the decimal point..
I predict that the number after the 1 is 4. Is it right?
Now add up the first six digits after the decimal point.
Your answer is 27.Yes Thats right.
How do I do it?
The six fractions 1/7 to 6/7 have the same repeating sequence of six numbers after the decimal point, each fraction starting with a different number in the sequence 142857. Think of these numbers as in a circle (Diagram A), and going around that circle forever.
The first number after the decimal point in the decimal version of 1/7 is 1 (.142857); of 2/7, 2 (.285714); of 3/7, 4 (.428571); of 4/7, 5 (.571428); of 5/7, 7 (.714285); and of 6/7, 8 (.857142). Adding 1, 4, 2, 8, 5 and 7, you always get 27.