This article describes an activity that incorporates measurement in order to lead students to discover and explore fundamental concepts of calculus. Students are provided with an experientially real starting point involving measurement and are encouraged to engage in mathematical discussions in a low-stakes environment. I describe the activity as it unfolded in my classroom, while indicating moments at which my students exhibited certain Standards for Mathematical Practice (National Governors Association Center for Best Practices & Council of Chief School Officers, 2010) and Process Standards (National Council of Teachers of Mathematics, 2000).