## The Anatomy of Black Holes - Page 23

Scientists believe that if an object reaches a critical radius near a black hole, the object will inevitably be drawn into the singularity. In mathematics, a similar situation can occur. Some mathematical expressions and operations will result in a numerical 'black hole' no matter where you start!

A. Follow the below procedure starting with a positive integer. We show you the results for the beginning values of 5 and 7.

Why does this procedure always give the answer 4? Let us examine the steps.

Go through the procedure again with the starting value of "B".

Notice that the final result is 4, regardless of the initial value. That is, all beginning numbers fall into the 'black hole' 4.

Now it is your turn. Can you create a numerical 'black hole' whose value is always 10?