To focus on mathematical reasoning and what makes a good argument, the authors developed an assignment that requires college students to submit a book of mathematical reasoning as an assessment during the semester. To begin, the authors looked for questions and tasks that lend themselves to developing mathematical arguments and justifications and…

Fostering students' mathematical thinking requires regularly presenting them with challenging problems and involving them in the processes of mathematical inquiry (e.g., representing and solving problems; making, testing, and justifying conjectures). The Inverting a 36 Penny Triangular Array problem (called the Inverting problem, for short) is a…