It’s the 42nd Carnival of Mathematics. Don’t panic!
First, the customary trivia about the number of the Carnival.
- 42, Jackie Robinson’s jersey number, is the only number retired by all Major League Baseball teams.
- 42 is a domino game, especially popular in Texas.
- 42 is the top result for the Google search “answer to life, the universe, and everything.”
And now on to the posts.
Next, Barry Leiba discusses the use of logic in mathematics in Modus ponens, modus tollens, and proof by contradiction posted at Staring At Empty Pages. The footnotes at the end have some interesting information on prime numbers, factorization, and cryptography.
Moving from philosophical logic to hardware logic, Himadri Choudhury illustrates how a seemingly trivial problem becomes interesting when you look into it deeply enough. He presents a clever algorithm for simultaneously adding three integers more efficiently in a microchip. Check out Multiple Operand Adder posted at Thread Pool for an insight into the work that goes into operations most of us take for granted.
Moving higher up the computing levels of abstraction, Samuel Jack combines mathematics and computer science in presenting his solutions to problems 18 and 67 from Project Euler. See Project Euler Problems 18 and 67: Finding the Maximal Route through a Triangle posted at Functional Fun. He also presents his solution to problem 15 in the same series in City Grids and Pascal’s Triangle.
Finally, MBB explains how the check-sum algorithm works on major credit cards in Generation Of Luhn Algorithm Credit Card Numbers posted at Money Blue Book Finance Blog. This algorithm will detect any error that changes a single digit and will detect most errors that transpose consecutive digits.