The more correct answers, the more clues and treasures and the more math-excited students. Each group has its own 2x2 meter plot to unearth. Each group done correctly, wins a prize. Let each group figure out best way to get all problems done. When 6 coordinates are reached, a map is received from the teacher.
Group goes outside to dig at the given coordinates and to find their treasures.
Each one must be labeled on the map in its correct place. Group turns in map to the teacher for final prize.