The Fraction Puzzle challenges students to use their knowledge of fractions, factors and exponents to unlock a series of instructions to build a model out of index cards using both the metric and standard measurement systems. By disguising the building instructions in mathematical riddles and requiring the use of both standard and metric measuring systems within the same project, students are able to demonstrate their skills as they analyze instructions and work towards a final product. Students are not told what the model will be but instead discover it during this constructivist lesson.