When teaching 3d shapes at KS2 I have always taught that a face is a surface of a shape, e.g. a cube has 6 square faces, a cylinder has 3 faces, 2 circular and, if you 'unwrapped' it, 1 rectangular. It would therefore follow that a cube has 8 edges and a cylinder has 2, as an edge is where 2 faces meet. However, on looking at maths definitions on the internet, I read that a face is only the FLAT surface of a 3d shape and a face is NOT a curved surface. Therefore a cylinder has only 2 faces and as the faces do not meet, no edges. I've checked the QCA glossary and they also seem to say the same - defining an edge as where 2 plane surfaces meet. However (again) the other Y6 teacher disagrees with the above and agrees with my previous explanantion ( hope you're all following this)! As a result, we have both taught different definitions, throwing us, and the poor children, into complete confusion! PLEASE can some maths wizard advise!