Without using any arithmetical symbols (+, -, *, /, or similar; other math symbols; decimal comma or periods; letters; even parentheses) or, in short, anything but the digits, build a number with the digits 1, 3, 5, 7 and 9, that is equal to a number built with the digits 2, 4, 6 and 8 (each digit used once and only once).

Note: This is not a trick. It was extracted from a book edited by Angela Dunn, a mathematician who gathered problems that appeared in many scientific periodical revues!

(In reply to Try a notation structure by brianjn)

"Powers!  With the Odd digit set, no matter what I take as my base, the others become my power index, and so give an odd numeral."

13 base 5 is 8, an even number.

Posted by Charlie on 2005-07-02 04:36:09