Your Sets of Teeth
ASK: How many teeth do newborns have? What does a baby eat? Why?
DISCUSS: Imagine a baby having all of your teeth! Would that many teeth fit into a baby’s mouth?
Newborns have no teeth that we can see, although their 20 baby teeth are formed under their gums. At first, babies can only drink liquids like milk. Then they eat soft baby food and foods such as applesauce, mashed banana, and mashed vegetables.
Baby teeth begin to push through a baby’s gums when the baby is about 6 months old, starting with the front teeth. By the time a toddler is about 2-1/2 or 3 years old, all 20 baby teeth have appeared.
Would an adult’s teeth fit into your mouth? Your mouth is not the same size as an adult’s mouth. You will have two sets of teeth in your lifetime. The first are your primary or baby teeth. There are 20 primary teeth. Your first set of teeth fit perfectly in your mouth. Later, your primary teeth fall out and your permanent teeth come in. There are 32 of them.
ASK: How many of you have lost a tooth? What was that like? Were you afraid? What happened? Why do you think your first teeth are small primary teeth, and your larger permanent teeth come in later?
DISCUSS: Permanent teeth are larger than baby teeth and wouldn’t fit into your mouth.
When you are about 6 years old, permanent molars in the back of your mouth begin to appear. Your front baby teeth may fall out to make way for permanent teeth. Up to about 12 years old, your permanent teeth replace baby teeth. In your teenage years, the last of your permanent teeth appear. They are molars called wisdom teeth. This set of 32 permanent teeth can last a lifetime if you take care of them.
- Activity: Wash your hands thoroughly. Use a mirror to count the number of teeth you have in your upper jaw. Now count the number of teeth in your lower jaw. Add them together. Wash your hands again. Write the total number of teeth for each student on chart paper or the board. Collect and record the data for all class members. Make a bar graph indicating the number of teeth each student has. (The number will probably range from about 16 to 24 for primary students.)
Lower Primary Students: Which class member has the lowest number of teeth? Which class member has the greatest number of teeth?
Upper Primary Students: Explore landmark data. What is the range of the number of teeth class members have? What is the mode? The median? The mean (average)?