Write 305 large on the IWB and give five seconds of quiet think-time before any hands go up. Take three hands-up answers, not open call-outs. Then write two or three pupil-suggested three-digit numbers beside it and read each aloud together. Keep this brief, the columns get built properly in the next step.

247: name each column in turn, two hundreds, four tens, seven units. Every column has something in it. After that, show the ten-times trade yourself with loose rods: lay out ten loose ten-rods, count them aloud, trade for one hundred-flat. Ask how many ten-rods make one hundred-flat and take the answer before confirming. Same with ten units for one ten-rod if time allows. Draw out the ten-times rule: each column worth ten times the one on its right.

408: point at the columns. If we forgot the zero and wrote 48, the 4 slides into the tens and the 8 into the units, a smaller number. The zero holds the place open. Let them see the slide, not just hear it.

530: the empty column has moved. Ask which column is empty now, the units, the number ends in nothing.

999: biggest number before running out of room, every column at nine. Ask what comes next and pause before anyone answers. Sets up the wrap.

This round is for talking it through together — pupils take turns at the board and the class agrees or corrects out loud.

Call a number under 1,000, then invite an individual pupil up to build it on the mat. Rotate four pupils across four numbers. Pick at least one number with a zero (e.g. 306 or 720) so the class has to reason about the empty column. After each build, ask the class 'does every column match the number we heard?' before confirming.

Pupils watching the board are checking the build, that watching is their part, so keep the pace brisk and revoice a good correction aloud. Four single builds with a quick class check is roughly nine minutes, not a quarter of the lesson.

These are the practice questions — one pupil builds at the board while the whole class says the number and names the empty column aloud first, then watches the build being checked. Keep the board work brisk rather than over-explaining.

Run the four targets in order. For each, ask 'what is tricky about the zero here?' before the pupil presses Check, 308 has an empty tens column, 740 and 909 each have a zero too. Use the on-screen check tick as part of your narration: 'yes, that's it.' Pupils who finish thinking ahead can mouth the next number, no desk work in this step.

Recap the three points quickly using a number from the lesson (e.g. point back at 408 for the zero, and back at the ten-rods trade for the ten-times rule). Keep it to under two minutes so pupils move smoothly into their activity-book practice page.