Today students will follow a code to create a mirror image.
The core idea of this lesson is symmetry.
One marker per pupil
Mirror worksheet: A downloadable worksheet with a vertical line down the centre. On one side, you can see dots forming half of an image.
Start with a quick discussion about symmetry, what the word symmetry means and where we might have seen it before.
Invite the students to share examples of symmetry they have seen: butterfly wings, leaves, faces, snowflakes, reflections in water, hearts, stars, some letters (A, H), shapes like squares and circles.
Open the slides below on your whiteboard and discuss the different images of symmetry in our environment. At the end of the slides, you will see images that may or may not be symmetrical. Discuss with the students why the image is/is not symmetrical.
Remember to ask yourself - Does the right side match the left?
Open the Mirror Robot interactive on your screen. The left half of the picture is already drawn; pupils must code the robot to draw the right half so the whole image is a perfect mirror.
Explain the goal: “Your program should mirror the left side exactly—same shape, same distance from the centre line, just flipped.”
Pupils add arrow steps in the game to join dots on the right side, then press Run to see if their code draws the missing half.
Hand out the Mirror Robot worksheet. Explain that this paper version works just like the game: the left half of a house is already drawn. Pupils must write the code (arrows) and draw the right half so the whole image is perfectly symmetrical.
Remind them of the mirror rule: It must be the same on both sides!
Pupils trace one move at a time from dot to dot on the right side, checking after each corner that their line is the same distance from the mirror line as the left side.
Circulate and coach quick “mini-debugs”: if a line doesn’t match, find the first step that went wrong, fix that step only, and continue. Early finishers can add extra details on the left (e.g., a window) and then mirror it on the right.
Conclude the lesson by gathering the pupils to share their completed symmetrical pictures. Highlight how reversing the instructions created a perfect mirror image, reinforcing the concept of symmetry. Encourage pupils to discuss what they noticed about the process, and praise their precision and debugging efforts. This wrap-up helps solidify learning and ends on a positive, rewarding note.
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