I use this assignment in my classroom as a cumulative assignment at the end of our environmental unit. Students are required to choose assignments that add up to 100 points. This is an excellent method of differentiation and the quality of work submitted is usually much higher because the students are allowed to choose what assignments are of highest interest to them.
No additional worksheets are required! This board encourages students to get outside into their own environment. Students can use a variety of resources to complete the tic-tac-toe board including their own backyard.