## Archive for December 3, 2021

### What an Amazing Date!

There are lots of good dates — meeting at a bookstore coffee shop for, well, perusing books and sipping coffee; spending hours playing Super Mario Bros. and Pac-Man at a retro video game arcade; and, of course, going to a open-mic comedy show where one of the performers tells nothing but math jokes.

But great dates? Well, those are pretty rare. My first date with my wife — where I took her to a hotel and “whispered” to her from the couch across the lobby — is an example, though the stimulating conversation and her perfect laugh may have contributed more than the elliptical ceiling. (Maybe.)

Few dates, however, can compare to today’s date:

12/3/21

Look at that beautiful symmetry! Marvel at its palindromic magnificence! The way it rises then falls, like a Shostakovich melody.

But wait… there’s more! Consider the following pattern:

1 × 1 = 1

11 × 11 = 121

111 × 111 = ?

That’s right! The number 12,321 is a perfect square! And not only that, its square root contains only 1s.

Moreover, check this out:

1 + 2 + 3 + 2 + 1 = 9

That’s right! It’s a square number, and the sum of its digits is also a square number!

Finally, here’s a KenKen puzzle that makes use of the number, though it’s not unique unless one of the digits is already filled in:

No matter how you choose to celebrate, here’s hoping your day is as great as the date!

The Math Jokes 4 Mathy Folks blog is an online extension to the book Math Jokes 4 Mathy Folks. The blog contains jokes submitted by readers, new jokes discovered by the author, details about speaking appearances and workshops, and other random bits of information that might be interesting to the strange folks who like math jokes.

## MJ4MF (offline version)

Math Jokes 4 Mathy Folks is available from Amazon, Borders, Barnes & Noble, NCTM, Robert D. Reed Publishers, and other purveyors of exceptional literature.