Pangea Jigsaw Puzzle
activity exercisesuggested grade levels: 9-12
view Idaho achievement standards for this lesson

Overview:
It is fun to think of the ancient continents fitting together like giant jigsaw puzzle pieces. It's even more fun to make a model out of salt dough and see for yourself how they used to fit together.

Materials:
2 cups (250 g) of flour (plain white, unbleached, or bread flour work best) Cookie sheet or pizza pan Dull table knife Hot pad
2 tablespoons of dry wallpaper paste 2 cups (473.2 ml) of water Acrylic paints Pencil
Several sheets of tracing paper 2 cups (192 g) of table salt Large bowl Spoon
Rolling pin Oven Paintbrush Scissors

Procedure:
You need to print the Pangea Puzzle Pattern. Here is what you do:
1. Enlarge the pattern on a copier as indicated on the print out. Carefully trace it and cut out the pieces. Set them aside.
2. Mix the flour, salt and wallpaper paste in the large bowl. Add 1 cup (236.6 ml) of water and mix, then slowly add as much of the rest of the water as you need to make a firm dough. The dough should not be runny, but should feel like stiff clay.
3. When the dough is sticking together but is still pretty crumbly, dump it out onto a floured countertop or table and knead it for about five minutes. Here is how to knead dough: Starting with a mound of dough, squeeze it and push it away from you at the same time, then pull it toward you, folding the top toward you as you pull. Next, turn the dough mound partway around and repeat what you did before. Continue to push, pull, and turn. It takes a little practice to get into the rhythm of kneading. Sprinkle the dough with a tiny bit of water if the dough seems too dry, or a tiny bit of flour if it gets too sticky.
4. Roll the kneaded dough out onto a lightly floured countertop or table until it's 1/4 inch (1 cm) thick all over.
5. Place one of the paper pattern pieces on the dough slab and carefully cut the dough with the dull knife following the edges of the pattern piece. Peel off the tracing paper pattern. Gently lift up the cutout dough and place it on the cookie sheet or pizza pan. Cut out all the other pieces the same way. Peel off the tracing paper pattern after you cut out each piece.
6. Salt dough must be dried very slowly or it will crack. It must also dry completely or it will get mushy and start to rot. Ask an adult to help you put the pan in a 170° F (76.6° C) oven for one hour. (If you are using a gas oven, leave the oven door halfway open during the entire hour. Do not use a microwave to dry salt dough.) After an hour, turn the oven up to 200° F (93° C) and dry the dough for 30 minutes more. (If you are using a gas oven, leave the door a quarter of the way open during this baking time.) After 30 minutes, turn the oven up to 250° F (121° C) and dry the dough for another 30 minutes. (If you are using a gas oven, keep the door closed during this baking time.) Ask an adult to help you take the pan out of the oven.
7. Let the puzzle pieces cool for 30 minutes, then tap one piece to see if it sounds hollow. If it does, it's completely dry.
8. Paint the pieces with the acrylic paints and let the paint dry. Be sure to wash out your paintbrush when you are done.
9. Put your puzzle together.

Handouts/Activity links:
These are links to access the handouts and printable materials.
geog9ho.pdf

Related Lesson Topics:
Geography: Geography Topics

Lesson Plan provided by Vita Taube, 2000
Idaho Achievement Standards (as of 7/2001) met by completing this activity: