Make a Periscope With Milk Cartons

Invite your child to play with the mirrors. Challenge your child to discover how to look at reflections from different angles. For example, show your child how they can see behind them by holding one mirror in front of them and one behind them.

Begin making the periscope by cutting off the tops of both cartons.

Cut out a square on one side of each carton, near the base of the carton opposite the open end.

Next, create slots that will hold the mirrors in place. To do this, turn the cartons on their sides so that the square openings are on your left. Next, measure the width of the carton base. Then, measure that distance up from the bottom on the right side and make a mark.

Use the ruler to draw a diagonal line from that mark to the bottom corner of the carton. Do this on both cartons.

Flip the cartons over and draw similar diagonal lines on the opposite sides of each carton.

Cut the diagonal lines. Don't cut all the way to the edge of the carton. The cuts only need to be as long as one side of your mirror. Make sure the cuts are thick enough to insert your mirrors.

Next, insert the mirrors into the slots. The reflective sides should be facing the square openings. Secure the mirrors in place with tape.

Test to make sure the mirrors are in the correct place. When you hold the cartons upright and look into the mirror through the square openings, you should be able to see your ceiling. Adjust the mirrors if they seem tilted or off-center.

Next, connect the cartons. Place one carton right-side-up with a mirror facing you and the other upside-down with a mirror facing away from you. The carton facing you should have a mirror at the bottom. The carton facing away should have a mirror at the top.

Tape the two cartons together to create one long rectangular tube. The upside-down carton should sit on top of the right-side-up carton.

Let your child play with the periscope. You'll never know when they might pop up!