Saturday, May 24, 2003

It has been  nearly 3 months since the last newsletter, so guess  I had better catch everyone up.  Running a non-profit website means that you can work on what is most fun.  It also makes it easy to defer other tasks like this newsletter.    Our host site had a major email server crash  a couple of weeks ago, so this list has been pretty thoroughly rebuilt.   So we'll treat this newsletter as a beta test of the restored setup.

But  I did want to let everyone know that the national finals of the MATHCOUNTS competition are scheduled to be televised on ESPN next Thursday, May 29 at noon, Eastern Time.  I hope to help establish this math program for 6th, 7th, and 8th graders here in Floyd County next fall.   There must be at least one future computer programmer in that group!   You can check out MathCounts at http://mathcounts.org

Here are the  "What's New" items since last time.

March 6, 2003:   A couple of weeks ago, a viewer introduced me to the TV game "Countdown: which appears daily on BBC British television.  It's apparently quite popular in Europe,   but is virtually unknown on this side of the ocean.  The game has word anagram and arithmetic expression finding components.  Here's my version, Countdown Plus, which solves the arithmetic side of the game plus at least one other problem.  The idea is to form a parenthesized expression from a given set of 6 input values which matches a given target value as closely as possible, and you have a whole 30 seconds to do it!    This version finds countdown solutions in a few seconds, but also solves a problem proposed last year in Expressions 2002, an expression solver which uses the digits 1-9 to form an expression which evaluates to the year.    That program used only + and × operations but allowed the digits to be concatenated into larger numbers (e.g. 12 or 45, etc.).  The challenge posed at that time was to solve the problem allowing parentheses, but without allowing concatenations of digits.  Today's program does that handily.

March13, 2003:  Playing with the Windows Calculator program the other day got me curious about real number arithmetic.  Why do they only allow 4 digit exponents in most cases?  Using the X^Y function why does it calculate 10^43429 OK, but give an error for 10^43430?  Why is there limit of 32 significant digits?    The result is today's Big Float program which  provides a glimpse into the world of arithmetic with large real numbers  (but not many answers to the original questions).

March 17, 2003:  A persistent viewer really wanted a 10X10 version of our Token Flip puzzle  posted a few months ago so here it is.  This in spite of the fact that neither I nor the program, nor anyone else I know of  can consistently solve random games larger than 5X5.  If someone analyzes this darned thing  and comes up with an efficient algorithm for solving, please let me know, so I can mark it complete and move on.