Print out both pieces of the calendar template. Cut out along the outside rectangle.
Fold the right piece over at the dotted line and attach with tape or glue to the left piece, so that the tree in the center lines up.
Print out the daily activity squares and cut along the outside rectangle. Parents should cut these out so the kids will be surprised as they open up each date.
Fold each activity square in half and then in half again, so that if creates a "door" with an image on the outside and the printed activity on the inside.
Paste or tape the back of each folded "door" to the advent calendar location with the corresponding number.
Attach a dot sticker (found at local craft stores) to each rectangle to keep it closed until that day when your child will peel off the sticker and read the activity underneath. Have fun!