Archive for the ‘Trick’ Category

Math magic with the number 9

Friday, February 1st, 2008

9 is a most interesting number. I'm sure that's largely because 9 is 1 less than 10 and most of us have 10 fingers (or digits) and we do arithmetic in a base 10 system. I've seen an amazing number of math tricks that take advantage of something called ...

How does Arthur Benjamin square 5 digit numbers in his head?

Wednesday, January 30th, 2008

Last month I blogged about mathemagician Arthur Benjamin and his amazing mental Math feats. Benjamin is a master of doing arithmetic in his head with lots of digits involved. In particular, he's able to square a 5-digit number without writing down partial results. How does he do it? I picked ...

Impressive Math magic with 16 index cards

Wednesday, January 2nd, 2008

Here is one of my very favorite Math tricks that's sure to impress your friends (and yourself the first time you try it). I learned this trick over 30 years ago and amazingly enough I still remember it. Take 16 index cards and prepare them as follows: Make a diagonal cut at ...

Amazing Math trick with paper, scissors, and tape

Tuesday, November 27th, 2007

Here's something fun, not too heavy on the Math unless you want it to be, and quite remarkable to those who haven't seen this before. You're going to create a Moebius strip, and variations on it, and surprise yourself and others when you see what you get when you cut ...