The note
How schools teach it now
Reflection and lines of symmetry are taught in KS2 maths, often on squared paper. The method: each point stays the same distance from the mirror line but on the other side. Things near the line stay near it; left becomes right for a vertical mirror.
5-minute kitchen-table activity
Stand a small mirror upright on the table. Put a spoon, a coin and a Lego brick on one side and look at the reflection. Ask your child what swapped sides and what stayed the same. Then lay the mirror flat along a different edge.
Worked example
A right-angled triangle has its right angle in the bottom-left corner. Reflect it in a vertical mirror line on its right.
- A vertical mirror swaps left and right, but top and bottom stay put.
- The bottom-left corner becomes the bottom-right corner.
Answer: A right-angled triangle with the right angle in the bottom-right corner
Common mistakes to watch for
- Turning the figure instead of reflecting it.
- Flipping top and bottom when the mirror line is vertical.
- Missing one small part that also needs to flip.
Encouragement
- Try saying
- “Check what's next to the mirror line. Lovely careful looking.”
- Rather than
- “Don't you know what a mirror does?”