The dashed line is the mirror axis.
The picture must look the same on both sides of the axis, just mirrored.
Here's how:
1. Look at a colored square on the finished side.
2. Count its distance to the axis.
3. Color the square at the same distance on the other side.
The colored squares show the solution.
Example
For parents
What does this exercise practice?
Understand axial symmetry and mirror figures across vertical and horizontal axes.
Common pitfalls
Children often shift the picture instead of mirroring it. A small mirror placed on the axis helps.
How to practice at home
Fold a sheet of paper, draw half a figure along the fold and cut it out. When unfolded, the symmetric figure appears.
Related: Pattern, Tiling areas, Shapes