Parents may have difficulties relating to mathematics curricula that focus on conceptual rather than procedural understanding (Remillard & Jackson, 2006) because such curricula engage students in activities that are different from those that students experienced in previous generations. We report on a case study that explored how parents make sense of conceptual-based curricula by engaging two parents with tasks from their children's curriculum. Our report details both the tasks with which we engaged the parents and their ways of thinking about mathematics that emerged as they interacted with those tasks. Our findings suggest that in some cases parents' previous experiences with their school mathematics interfered with their ability to make sense of the tasks in a manner consistent with the curriculum authors' intent. However, we also found that their previous experiences with informal mathematics could be leveraged to support their endeavour to make sense of tasks from a standards-based curriculum in a manner consistent with that intended by the curriculum authors. Nevertheless, we also believe that the school-based tasks used in the study encouraged parents to interpret their children's curricular materials in terms of their own experiences with school mathematics rather than in terms of their informal knowledge. This study contributes to researchers' understanding of the complex process of sense making that is necessary for parents (and adults in general) to relate to standards-based mathematics curricula, and it raises questions about how parents might be supported in that process.