Anna asked if she could tape together a whole bunch of sheets of paper to make a giant snowflake. My boring adult brain immediately thought "That's a waste of a whole lot of paper." Then my real brain took over and thought "That's an excellent use of a whole lot of paper!"
"Okay," I said, "but only if I can help!"
What a project! First we had to tape together dozens of sheets to fill as much floor space as possible. Maggie came to watch and we had a conversation of European paper sizes. One sheet is A4, a double sheet is A3, double that to get A2, double again for A1, and one more double gives A0 which has area exactly one square meter. Ours was larger than A0, "Anegative1" Maggie suggested. As we got near the end, Anna and I had a good discussion about whether we needed to add one more row or one more column to get it as square-like as possible. We pulled out a tape measure and figured out the dimensions as it was and how it would be with one more row or with one more column.
Then the folding and cutting (with some more good math to measure 60° – precision is important with so large a model). After each cut we needed to retape parts that had come loose, because we didn't tape the complete edges of the paper together, that would have used too much tape.
Finally, the unfolding and a beautiful thing. Now if only we had a window large enough to hang it...