As a child grows, some of the bones fuse together so that in adulthood there are how many bones?

In adulthood, the human skeleton typically consists of 206 bones. This number is derived from the process that occurs as a child grows; certain bones in the body, such as those in the skull and spine, fuse together during the developmental stages. For example, the infant skull contains several fontanelles or soft spots that allow for growth and passage through the birth canal, which fuse to form a solid structure as the child matures. Additionally, the sacral vertebrae, which are initially separate, also fuse to form a single sacrum in adulthood.

As a result of this natural fusion, the number of bones decreases from around 270 at birth to the standard 206 in adulthood, making this the correct answer. Understanding this process is crucial for grasping human anatomy and the changes that occur over a person's lifespan.