- Two cardboard tubes (one wider and one narrower)

- Two plastic or glass lenses

- A piece of aluminum foil

- A rubber band

- Black paint

- Scissors

- A ruler

- A pencil

- A box cutter

Instructions:

1. Cut the wider cardboard tube in half lengthwise.

2. Cut the narrower cardboard tube in half lengthwise.

3. Glue the two halves of the wider tube together to create a tube that is twice as long as the original.

4. Glue the two halves of the narrower tube together to create a tube that is twice as long as the original.

5. Paint the inside of both tubes black.

6. Cut a hole in the center of one end of the wider tube. The hole should be large enough to fit the narrower tube.

7. Insert the narrower tube into the hole in the wider tube. The narrower tube should be about halfway inside the wider tube.

8. Cut a piece of aluminum foil large enough to cover the end of the narrower tube.

9. Attach the aluminum foil to the end of the narrower tube with the rubber band.

10. Insert a lens into the end of the wider tube. The lens should be facing the aluminum foil.

11. Insert the other lens into the end of the narrower tube. The lens should be facing the aluminum foil.

12. Adjust the position of the lenses until the image of a distant object is clear.

13. You have now built a telescope!

Tips:

- Use high-quality lenses for the best results.

- Make sure the tubes are straight and the lenses are aligned properly.

- Experiment with different focal lengths to find the best magnification for your telescope.

- Build a mount for your telescope so that it can be pointed at different objects in the sky.

- Observe the stars, planets, and other celestial objects at night.