Lab Coats - Ask children to bring in an old white shirt that their parents don't want any more, or go to a thrift store and buy one for each child in your room. Cut off the sleeves and write "Dr. child's first name" on the pocket. When you do science experiments, have them wear their lab coats and call them "Dr. Amy" or "Dr. Juan."
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Entomologists and Meteorologists - One teacher explained that whatever they were studying in science, she called the children by the scientific name. For example, when they studied insects she would call them "entomologists" or when they studied weather they were "meteorologists."
Paleontologists - Give each child a canned biscuit and a small plastic dinosaur. (You can order these from Oriental Trading or buy them at a party store.) After children mold the biscuit around the dinosaur, bake in the oven according to directions. Children take toothpicks and "dig" out the dinosaur. Of course, they'll be so hungry from all their hard work they will need to eat the biscuit when they are finished!