Flap books are quick to make with minimal supplies. Depending on the number of flaps, they can be completed in as little as 15 minutes. Supplies include one 8 1/2 x 11-inch sheet of paper and scissors.
Make the folds
Fold the sheet of paper in half vertically (known as a hot dog fold). Take the vertically folded paper, and fold that in half horizontally (hamburger fold).
Make the cuts
Unfold the paper fully. With scissors, cut along the vertical fold from the top of the paper, down to the horizontal fold. Don't cut below the horizontal line or the flaps won't form correctly. Fold the paper back into a hamburger fold. You have finished a 2-flap book.
Make more flaps
To make more than two flaps, always start with the same hot dog fold as for the 2-flap book, To make a 4-flap book, make a hamburger fold, then make another hamburger fold. Open the paper to find one vertical line and four horizontal lines. For an 8-flap book, do the same as the 4-flap version, but make one additional hamburger fold to produce eight horizontal lines.
Add more cuts
Instead of cutting down the vertical line as for the 2-fold flap book, cut along each horizontal line up to the vertical line (halfway across the paper). Refold into a hot dog fold, and you have produced a multi-flap book.