Multiple choice general knowledge You're born with 300 bones, but by the time you become an adult, you only have 206. True False Reveal answer Fill a bubble to check yourself A Correct answer Explanation Humans are born with approximately 300 bones, but many fuse together during growth. For example, the skull bones separate at birth but fuse, and vertebrae fuse to form the sacrum and coccyx. By adulthood, humans typically have 206 bones.