Quan, Daniel, and Sol, from blinkdagger and Wild About Math!, have teamed up to create a fun math contest, Monday Math Madness. Every other week, they post a math problem; after one week, a winner is randomly selected from among those sending in a correct answer, and receives a real honest-to-goodness prize!

The current contest was just posted today. Go give it a try, and send in your solution — maybe you’ll win! Even if you don’t, of course, it’s still a fun problem. Here it is:

Aside from 1 and 9, are there any perfect squares whose digits are all odd? Justify your answer.

Don’t post any answers or discussion here! If you think you’ve solved it, send your answer to mondaymathmadness at gmail dot com.