Show the half-butterfly image as pupils settle. Take two or three hands-up answers, not open call-outs. Don't reveal the rule yet — just let them sense that the missing spot has to sit the same distance from the line, on the opposite side.

Static display, point and count from the line, don't drag.

Keep the first two brisk, slow down on the last two.

One out: square one left of line, mirror one right. Same distance, opposite side.

Three out: count 'one, two, three' aloud on each side so the matching count is heard.

L-shape (3 squares): ask them to predict where it lands first. Reflect each square on its own distance, not the L as a lump. Whole L flips to face the other way.

On the line: the trap. Ask them to predict. A square on the line doesn't move, it is its own mirror.

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

Place two or three squares on one side, then call a pupil up to reflect each one. Ask the class to count the distance aloud before each placement: 'how many squares out is this one?' Watch for the common slip of placing the mirror one square too near or too far from the line — catch it by re-counting together. Rotate a few pupils through the placements.

These are the practice questions — pupils take turns at the board, check each answer, and the class confirms before moving on. Keep the board work brisk rather than over-explaining.

The square-on-the-line round is the make-or-break check: that square sits on the line and does not move. Re-count distances aloud whenever a placement wobbles, and ask the class to predict before confirming each answer.