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.
Teething patterns vary greatly from child to child â some don't have any teeth at their first birthday, while others are sporting a mouthful by then. The vast majority of babies sprout their first teeth between 4 and 7 months of age.y age 3, your child should have a full set of 20 baby teeth, which shouldn't fall out until his permanent teeth are ready to start coming in, around age 6.