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 to Expect Teething to Begin. Most babies' teeth begin to erupt between the ages of 4 to 6 months, though for some it may be earlier or later, Dr. Josen says. And no matter what Grandma says, when your child's first tooth pops in, it has nothing to do with smarts. The age the baby cuts his or her first tooth depends on family history of teething and nothing more, says Jill Lasky, D.D.S., a pediatric dentist at Lasky Pediatric Dental Group in Los Angeles. So, if you got your teeth early, your child probably will too. Same thing if you were late.