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Focus with multiplication. Focus Secret

Spectacular tricks and their clues

Directory / Spectacular tricks and their clues

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Focus Description:

In this focus, we will rely on the fact that digital root the product of the digital roots of two factors is equal to the digital root of the product of these factors. So, you can ask someone to write down a fairly large number, say five or six digits, and sign another large number below it. Watching how the numbers are written, you determine the digital roots of both factors, multiply them and find the digital root of the product.

Now you turn your back and invite the viewer to multiply the numbers they wrote down. Then ask him to circle any number of the result (except zero) and say the rest of the numbers aloud in any order.

Focus secret:

You will find out the marked number by subtracting the digital root of the set of numbers named by the viewer from the digital root that you had to remember. If the second root is greater than the first, again, before subtracting, add nine to the first of them.

Author: M.Gardner

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