Preparation materials: colored cardboard, scissors, glue, compasses or bottle caps.

1. Roll the yellow square card paper into the shape shown in the figure below and glue the edges.

2. Cut off the extra parts so that the top is flat.

3. What it looks like after cutting

4. Fold the blue square cardboard into a small square.

5. Draw a circle with compasses or bottle caps.

6. Cut it out and form several small circles.

7. Fold them all in half

8. Apply glue at the position shown.

9. Two stick together

10. Glue all the disks together.

1 1. When the glue dries, tidy it up and turn it into a ball.

12. Put this ball into the finished cylinder, apply a little glue at the contact position and stick it well.