Here are a few examples that I found of #mathinmyworld!
Patterns, Fractions, 3D shapes
(And I just came up with the question, How many triangles do you see?)
I'm going to keep this idea fresh in my mind so that I can use it with my 4th graders in the fall. I'd love to be able to have them put together some sort of collection of math they find in their world so that we could share it and have others add to it. Hmmm....