A mirror line runs down the middle. The left half is already done, the right one is yours.
This is how you find every square: count how far it is from the line on the left, then go the same distance on the right.
The first example is colored in. In the second one you draw instead of coloring, line by line on squared paper. Count the squares along each line to do it.
The colored squares and the thin lines below show what you have to add.
Examples
Example: Coloring
Example: Drawing
For parents
What does this exercise practice?
Completing a shape to make it symmetrical trains spatial awareness and careful looking.
Common pitfalls
Children often copy the half one to one instead of mirroring it. What is on the far left belongs on the far right.
How to practice at home
Fold a sheet of paper down the middle, draw a pattern on one half, and check where it lands on the other side.
Related: Continue the Pattern, Magic picture