Hold up (or show a photo of) a ball, a tin and a dice. Give five seconds of quiet think-time, then take three hands-up answers, not open call-outs.

Listen for the idea that the round parts do the rolling — you'll return to this at the end. Don't confirm or correct yet; let the wondering hang.

Point to each card as it settles and name one telling feature: a cube — every face is a flat square, like a dice; a cuboid — a box shape, like a cereal box; a sphere — fully round with no flat face at all, like a ball; a cylinder — a tin, flat round on top and bottom; a cone — an ice-cream cone that comes to a point.

Take one everyday example from the class per solid before moving on. Hold out for the sphere being the only fully round solid — that is the one that catches people out later.

Talk this one through together — pupils take turns at the board and the class agrees or corrects out loud. For the quick items, use a turn-and-name: ask one pupil to name the solid and one telling feature before the drop, so more voices join in.

Work the pictures in the order they are named so the round-versus-flat idea builds. Ask which telling feature tells you its name? before each drop. When you reach the globe, hold out for the idea that a sphere is fully round even when it has a picture drawn on it.

This is the practice round. Start on the board with the roll-or-slide sort the interactive supports: the class confirms each solid aloud before the next one drops. A curved-surface solid counts as rolls for this binary sort, so the cylinder and cone both go in Rolls.

Then move to the real tray in pupils' hands for the harder rules, which are called one at a time. Flat-faces-only pulls out the cube, cuboid, cylinder and cone. Box-shaped isolates the cuboid. The last rule leaves only the sphere. This is where the cylinder and cone earn a closer look: they roll, but they also have flat faces, so with the real tray they can sit in more than one group depending on the rule. Revoice: a cylinder rolls, and it also has flat ends, so it fits the flat-faces group too.