As I was reviewing blog posts and webinars from the Library of Congress, I found a good community builder that might be useful, especially for remote learning. The activity is called "Hide and Seek", and the example used the picture shown here. You can find the entire webinar with a couple more activities and a bunch of ideas here. (Scroll down to the May 27th entry.)

Brainstorming with a colleague, there are also a bunch of number-related questions of various levels we could ask about this picture: How many people are in the picture? If the buildings shown have stores on the ground floor, and apartments above, how many apartments might be visible in this block? The photo was taken in New York City around 1900; what was the population of NY at that time and what was the population density? Could we use this picture to estimate the population density? These questions are not necessarily the most profound things to ask, but maybe learning to ask questions could be the bigger idea here, rather than just finding the answer to a problem.

Solving problems is something we do quite a bit in math classes, but I (and I know many other teachers) try to incorporate reasoning skills and other practice standards into my lessons. So I've been thinking quite a bit about how primary sources like this are related to math classes, and at this point, I've come up with a few general categories. We can use primary sources to ...

- practice asking math questions (like we did for the picture above)
- jump into a modeling activity, where students have to solve an ill-defined problem by making and identifying assumptions, defining variables, and practicing an iterative solving process
- engage students with a story or historical context for the math ideas
- represent data and interpret data representations (and the biases inherent in those representations)
- connect math ideas to students' experiences by looking at documents through different lenses: mathematical, historical, personal, or social justice
- make clear connections between thinking skills they use in other classes and in life and ways of thinking mathematically, like identifying facts versus inferences or asking open versus closed questions
- spark inquiry-based learning activities.

Picture Source: Detroit Publishing Co., Publisher. Mulberry Street, New York City. Photograph. Retrieved from the Library of Congress, <www.loc.gov/item/2016794146/>.