[ *September 28, 2013* ]

A question about ninedigitals

by Mike Fairley (email)

Can someone please explain why 123456789 multiplied by 2 has

every digit (246913578) and divided by 2 also has every digit

(61728394.5) and one can continue to multiply by 2 or divide by 2

for a few more times and the result always has every digit.

Is this common knowledge or does it have a simple mathematical

proof which is eluding me?

I am wondering if someone may have a simple mathematical explanation.