I ran across this X Marks the Spot Puzzle several years ago. The goal of the puzzle is to place Xs in the drawing so that a certain set of requirements is met.
After typing up this puzzle with several other brainteasers, I promptly misplaced the computer file before ever using any of the puzzles with my students. Several months ago, I ran across the file and decided I needed to use the puzzles in my classroom and share them here on the blog.
Sadly, past me was not always the best at recording the source of the puzzles I found. I have searched and searched and searched, and I cannot find this puzzle online anywhere. If you know of the original source, please let me know so I can give credit where credit is due!
In X Marks the Spot, you are tasked with placing Xs in a drawing to meet certain requirements. Place Xs in the drawing so that:
- exactly two Xs are within the triangle and circle only,
- exactly two Xs are within the square and circle only,
- exactly five Xs are in the triangle, and
- there are a total of ten Xs within the circle.
I plan on using this puzzle with my students in a dry erase pocket to make it easy for them to draw/erase Xs.
Free Download of X Marks the Spot Puzzle
Digital Version of X Marks the Spot Puzzle
Kathy Henderson has created a Desmos Activity Builder version of the X Marks the Spot Puzzle.