Anyone know what this is?

My Mom and I picked this up at Goodwill awhile back, and I have no idea what it is? I have done a million Google searches, but haven't found anything remotely similar. 

So I come to you, my fabulous readers to find out what it is! 

It is 12"x12" and fairly heavy.

Here are a few shots of the numbers. They are increments of 6, but I am unsure what the measurements are - they are not inches or millimeters. The entire length of the "ruler" is 7.5".

And here is the back:

Any ideas??? I would love to hear them!

**Update**
Thank you, my wonderful readers, for the great responses! I would have never guessed it was a pill tile - never in a million years! So a $5 buy from Goodwill, not bad.

Color Me Happy ~

I recently purchased a new set of Prismacolor Premier Colored Pencils. 

This set runs around $180, but I got mine for $90 from Ebay - thank you Ebay!! I decided they needed to be out of their box and easily accessible.

So I grabbed whatever glassware I had handy. And let the color coordinating begin - the kiddos enjoyed helping me "sort" all of the colors. 

I have got to say, colored pencils (really any art supply for that matter) really makes me smile. 

I love all of the colors...just waiting to create. 

I realize that the computer is now one of the most popular "mediums", but I still love the old fashion pen to paper. 

How about you, is there a specific art supply that makes you smile?