Putting some teeth into learning

Archana Dwivedi

Lorraine Boissoneault (journalist and writer) writes in an article*, “Ten thousand years ago, Mesolithic hunter-gatherers of the Croatian Peninsula caught fish (perhaps using their teeth to remove the scales) and foraged for starchy plants.” How do archaeologists know about human beings who lived long before us just from fossil remains? The answer, by studying the teeth found at the site. Teeth can take us on a journey back in time and tell us the story of the past. The story of our evolution, our ascent on Earth, our common history of transforming into Homo sapiens.

Can we make the study of teeth, so valuable and significant to the archaeologist, useful in the classroom as well? An understanding of teeth is important to introduce the evolutionary trajectory and food habits of an organism. In addition, the study of teeth is useful to take care of one’s dental health. In my teaching, I have experienced that students easily appreciate that there are variations in teeth among human beings. And this could be used as an opportunity to find patterns in the variations. However, it is also important to take care that students develop an appreciation towards variations as a natural phenomenon and not look at them as aberrations or exceptions. A focus on the structure-function relationship of different kinds of teeth will also help children learn about the food habits of different animals.

With these ideas in mind, I planned the lesson for the chapter A busy month from the grade 4 NCERT EVS textbook. The chapter largely talks about birds and the last section introduces the teeth of different animals while comparing them with the beaks of birds. In this article, I present a narrative of how I introduced the topic in the classroom and how the students responded to the tasks given to them.

Introduction of the topic
Me: Do all birds have similar beaks?
Students: No (in unison).
Me: Why are there variations in birds’ beaks?
Students: Birds have different food habits.
Me: How do they eat?
Students: Birds swallow.
Me: Do they have teeth?
Students: Yes (some), No (many).

The students who had answered “yes” confirmed that they had not really observed birds; on the contrary, those who answered “no” had observed birds. On asking about how other animals eat food, the students answered that they chew. They also added that these animals chew with their teeth and have different types of teeth. They said that the lion and dog have sharp teeth to tear flesh, rat and squirrel gnaw objects with their sharp front teeth, while the cow has flat teeth to chew grass. For the snake, some students said that their sharp teeth help to hold prey while swallowing, others reasoned that the snake’s teeth help them bite.

Exploring our teeth
Next, the students were asked whether every human being’s teeth looked the same and how many teeth they have. Many students gave random answers and only a few were able to mention the actual number. This provides a meaningful context for students to estimate. Another advantage of this is that the estimated number can be verified later. It is interesting to note that students who find it difficult to count are also poor in estimating numbers. This exercise will give them an embodied experience of numbers.

After noting down the estimated value in their notebooks, the students were asked to explore their partners’ teeth. They counted their partners’ teeth and drew images. Though their count was mostly correct, their drawings did not correspond with the actual number of teeth counted. This is another context of counting where students had to obey one-to-one correspondence#. For this exercise, the students could invent different strategies to count efficiently looking at the symmetry of arrangement. For example, the number of teeth in the lower jaw is the same as the number of teeth in the upper jaw. And in each jaw, there is an axial symmetry. To be able to use symmetry in counting is an important skill.

The students’ drawings of teeth can be put under three heads:

1. Based on jaw and view: Three students drew both jaws and front view. While one drew only one jaw and top view. Drawing the jaw allows one to show the side and top view, which is part of the chapter The Way The World Looks in the grade 4 NCERT mathematics textbook and the chapter Where to Look From in the grade 3 textbook.
2. Correspondence to the actual number of teeth: Though students attempted to represent the actual number of teeth in their drawings, not many managed to. One reason was that they drew the front view, which did not allow them to show the teeth inside the mouth. They had a similar problem even in the top view drawings.
3. Correspondence to the actual shape: Clearly students made the effort to draw as per the shape of the teeth, but drawing a fixed number of teeth in an already drawn outline became a problem. They also faced difficulties while detailing the shape as is evident from their drawings.
   

It is noteworthy that the students identified three kinds of teeth – incisors, canines, and molars. The students could not distinguish between the pre-molars and molars and therefore counted them together.

Showing teeth of different animals and making teeth
Students were shown images of the teeth of different animals such as the cow, cat, snake, squirrel, and human.

Four students^ were asked to make models of the teeth and jaw using clay (other students were given different tasks related to the chapter we were studying). They made the teeth with the help of their fingers and used their nails to give fine shapes. Finally, they placed their product on cardboard.

Support from teacher and students’ learning
Support from the teacher was limited to providing images, giving tasks, and supplying clay and cardboard. There were no instructions provided during the work, nor did the students ask for any. While doing this activity, the students developed an idea of the different structures of the teeth, specific details of a particular kind of structure, and its possible functions.

I held a discussion in the class after the model making task. I asked whether all animals have the same kind of teeth. The students gave insightful responses based on their knowledge. They responded saying that the teeth would vary based on food habits like in herbivores, carnivores, and grazing animals. They also inferred that the size of the teeth will increase with the size of the animal. In response to the question on the functions of teeth, the students said biting/dasna, hunting/shikar, tearing, chewing, and eating. When I asked what will happen to us if we don’t have teeth, the students replied that we will find it difficult to eat food, will not be able to tear meat, chew, or bite, and only drink and swallow. It was interesting that many of them said we will not be able to speak, two students said it will be difficult to produce sound, another two students believed there will be no difference between the voices of the old and young.

Conclusion
Overall, the lesson was satisfying for both the students and me. After making the teeth models, the four students had a sense of accomplishment. The idea behind making teeth was to get them to feel the shapes and anticipate possible functions as well as note the variations in the teeth of the same animal. These models were displayed in the Science Day exhibition in school.

While this time, the models were made only by four students, the next time I plan to ask all the students to make models of teeth and get students to carry out simulated tasks to verify the perceived functions of different shaped teeth. These functions would be discussed along with food habit, overall structure and behaviour of the organism and connected with evolutionary history. While my students used clay, this activity can also be done using wheat dough and the models can be used as display or TLM for teaching higher or lower classes.

*Lorraine Boissoneault (2018).How Ancient Teeth Reveal the Roots of Humankind: From diet to evolution, prehistoric chompers tell archaeologists a surprising amount about our ancestors. Available online https://www.smithsonianmag.com/category/science-nature/

#A method of counting, where the child counts by assigning one number to one item in a sequence.

^These four students were not at par with their classmates when it came to reading, writing, and counting. So the exercise they were given tried to include these skills.

The author works at Azim Premji Foundation. She can be reached at archanadwivedi31@gmail.com.