Prepare materials and tools: a cake box, a piece of red and black cardboard, Five thumbtacks, a lunch box, double-sided tape, and scissors.
1. Cut the red cardboard into a circle.
2. Use thumbtacks to fix the cardboard on the paper box.
3. Cut an arrow-shaped pointer from black cardboard.
4. Use a thumbtack to fix the pointer in the center of the red cardboard.
5. Glue the bottom of the lunch box and the top of the paper box together.