*[Feature photo (above) by Alex Kehr. Photo (right) by kirstyhall via flickr.]*

Welcome to the *Math Teachers At Play* blog carnival — a smorgasbord of ideas for learning, teaching, and playing around with math from preschool to pre-college. If you like to learn new things and play around with ideas, you are sure to find something of interest.

Let the mathematical fun begin…

## PUZZLE 1

By tradition, we start the carnival with a pair of puzzles in honor of our 58th edition. Click to download the pdf:

## PUZZLE 2

A **Smith number** is an integer the sum of whose digits is equal to the sum of the digits in its prime factorization.

Got that? Well, 58 will help us to get a better grasp on that definition. Observe:

58 = 2 × 29

and

5 + 8 = 13

2 + 2 + 9 = 13

And that’s all there is to it! I suppose we might say that 58′s last name is Smith. [Nah! Better not.]

- What is the only Smith number that’s less than 10?
- There are four more two-digit Smith numbers. Can you find them?

And now, on to the main attraction: the blog posts. Many articles were submitted by their authors; others were drawn from the immense backlog in my Google Reader. Enjoy!

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