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.
In general, baby teeth start to appear between 4 and 7 months old, but each baby is different. The first teeth to come in are usually the 2 bottom front teeth. The process of your baby getting teeth is called teething. When your baby starts teething, you may notice that they drool more or want to chew on things.