Bring a poinsettia plant into class, and tell the children a short Spanish legend about the origin of the poinsettia. The book "The Legend of the Poinsettia" by Tomie dePaola is a good choice.
Tell the children they are going to make their own special poinsettias with their hands. Hand out a piece of green construction paper, black marker, red tempera paint in a paper cup, a paintbrush and painting smocks to all the children.
Spread out newspaper over each of the student's desks while they put their painting smocks on.
Instruct the kids to write their names in the upper right-hand side of the construction paper with a black marker.
Tell the students to take the paintbrush and paint the palm side of one of their hands with the red paint and then press it down onto the paper. Help them do this three more times at 3 o'clock, 6 o'clock and 9 o'clock from the original hand-print. The palm portion of the prints should overlap. This will create the leaves of the poinsettia.
Instruct the kids to wash the tempera paint off from their hands and return to their seats but not to remove their smocks.
Give the children a paper cup with yellow tempera paint and a new paintbrush.
Show them how to place 10 yellow spots in the center of their poinsettia picture to create the cyathia.
Show the children a world map and help them locate Mexico in relation to the United States. Then explain that most children in Mexico celebrate Christmas just like we do, except they do it for 10 days.
Introduce the story of Mary and Joseph trying to find a place to stay the night that Jesus was born. Retell the story of their journey and how they were not given shelter by many of the innkeepers in Bethlehem.
Explain that the Spanish tradition of Las Posadas is the re-enacting of this part of the Bible story and that families take turns playing the role of Mary and Joseph from Dec. 16 until Dec. 24. They walk to their neighbors houses and ask for shelter, and the neighbors refuse (often in song) and then join the group to go to the next house. This continues until they reach the home that will represent the inn that gave shelter. The families will enter and say a prayer around a nativity scene (often the rosary).
Break the students up into nine equal groups and have them arrange their desks into "inns" of their own. Have each group take a turn going from door-to-door asking for shelter. When they reach their starting point, the teacher gives them shelter there.