How can you fold a piece of paper into an envelope without using tape?

To fold a piece of paper into an envelope without using tape, follow these steps:

1. Fold the paper in half horizontally.
2. Fold the top corners of the paper down to meet the center crease.
3. Fold the bottom corners of the paper up to meet the center crease.
4. Fold the bottom edge of the paper up to meet the bottom of the triangle created by the previous folds.
5. Tuck the top flap into the pocket created by the bottom fold.
6. Your paper is now folded into an envelope shape.