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.
It can be hard to determine what teeth are baby teeth and which ones are permanent. Your baby's first tooth makes its grand debut around 6 months of age, and by two to three years old, all 20 baby teeth should have erupted in their mouth. Six years old is when you can expect your children to lose their first baby teeth and have permanent teeth peek through.