Math “Unit” Studies? Bringing Math alive

I am looking for a “unit” study- I use that term lightly – I want something fun that requires my kids to apply math (2nd grade). My friends daughter did a study at ps where she earned “money” by answering math questions and then spent the money buying live stock and setting up a farm. Each animal required so much space (she did this on graph paper), so as she figured out how much she earned she got to buy horses, chickens, cows, etc and set up this farm. Then she got to color, draw and cut out her animals – sounds like great fun for my kids. I am sure that I could re-create this, or something like it, but my plate is already so full! Does anyone know of anything like it???