Quick Answer. An experimental variable is something that a scientist changes during the course of an experiment. It is distinguished from a controlled variable, which could theoretically change, but the scientists keep constant. Continue Reading.
While you were pregnant, your baby developed tooth buds, the foundation for baby teeth (also called milk teeth). Very rarely, a baby is born with a tooth or two, or grows a tooth in the first few weeks of life. But the vast majority of babies sprout their first tooth sometime between 4 and 7 months old.
As your child develops and grows, they will grow and lose teeth. A baby's teeth start to come in around six months old and by age 3; most children have a full set of primary teeth. Baby teeth will be lost to make space for their adult (permanent) teeth, which begin to come in around age 6. The first molars usually appear between 9-11 years and a person usually has all of their adult teeth by age 21.