A five digit number 82093, constructed by 29 matches looks like this:

  _    _    _    _    _ 
 |_|   _|  | |  |_|   _|
 |_|  |_   |_|   _|   _|

You are requested to make this number as big as possible by moving only two matches.

What is the maximum value and how is it achieved?

What would be your answer if 3 matches were allowed to be relocated?

Be creative - no restrictions re your answers.

(In reply to re(6): restrictions - no spoiler by Jyqm)

While Google might have a problem with it, you can get a free account at www.sagenb.org, and start a new notebook and request this value.  On screen, the result is truncated, but you can ask to download a text file with the result. It has all 77831 digits, starting 986713779104027508518112553418782869522924495867... and ending ... 39925365345721620045016330070697675182758450107123207.

The site was described in Mathematics Teacher vol. 107, No. 2; September, 2013. (pp. 144-148).

92097 * log(7) verifies the number of digits and the beginning few digits, and in UBASIC, ?modpow(7,92097,100000000000000000) verifies the last few digits.

Edited on January 26, 2014, 10:54 am

Posted by Charlie on 2014-01-26 10:49:48