Display the photo and take three hands-up guesses, not open call-outs. Don't confirm a right answer — the point is to get pupils comparing the sizes of the three containers before any measuring. Which one holds the most? Which holds the least?

Read each level aloud as the class watches: five hundred millilitres — half full, one litre — right to the top, two hundred and fifty millilitres — a quarter, seven hundred and fifty millilitres — three quarters. Hold out for the big idea: 1000 ml makes 1 litre, so the litre mark and the 1000 ml mark are the same line. Point to the level, not down from the top — mention reading at eye level.

Talk this one through together at the water tray — pupils take turns and the class agrees or corrects out loud.

Real containers circulate. Before each pour, take a quick whole-class estimate (write the guess up) so the watching pupils stay with it; then the named pupil pours into the jug and the class reads the level aloud. Revoice the reader's answer each time so everyone hears it. Reconcile any disagreement by pointing to the mark the water sits on. Read at eye level, not looking down. Keep the pouring brisk. Listen for pupils naming millilitres for the small amounts and comparing to the 500 ml halfway line.

This is the practice round at the water tray — real objects circulate around the room and pupils measure each one, checking the jug reading with the class before moving on. Keep the pass-on rhythm brisk; the class confirms each reading aloud at the end.

The egg cup is a small ml amount (well under 100 ml) — hold out for the smallest reading. The challenge pushes the 1000 ml = 1 litre link: pupils add two of their readings and check against a litre. Circulate and prompt is that closer to 500 ml or to 1 litre?