Place value underpins much of what people do in number. In this article, the author describes some simple tasks that may be used to assess students' understanding of place value. This set of tasks, the Six Tasks of Place Value (SToPV), takes five minutes to administer and can give direct insight into a student's understanding of the number system and therefore what teaching is needed. It can be administered to students generally from Year 3, as this is when this understanding is expected to be achieved by most students. This is also when some students' conceptual understanding and procedural learning of arithmetic becomes less integrated and can contribute to mathematical learning difficulties. The highly integral nature of understanding place value numeration as it is applied in arithmetic and problem solving is acknowledged as is the range of ages at which students can establish this understanding, if they do. This set of tasks therefore aims to support teachers in validly exploring their students' understanding so they can ensure this crucial conceptual aspect of mathematical learning is well established.