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.
When Do Babies Get Teeth. It is completely normal for your baby to get her first tooth at 18 months. And there are rare cases when an infant is born with teeth. For most children, however, that first tooth will appear around six months. < Teething Symptoms. 1. 2.