In this article, Kym Fry uses the "Programme for International Student Assessment" (PISA) assessment framework to break down what her Year 6 students learned as they explored the inquiry question, "How much is a cubic metre?" First, an overview of the lessons in the unit is provided. Quality assessment opportunities are highlighted and where possible, so are links to the PISA assessment framework. Next, the PISA competencies are briefly explained to illustrate a way of thinking about student inquiry learning. Finally, implications for the classroom are discussed.