Babies have more than 100 bones than adults

Babies have about 300 bones at birth, with cartilage between many of them. This extra flexibility helps them pass through the birth canal and also allows for rapid growth. With age, many of the bones fuse, leaving 206 bones that make up an average adult skeleton.

Reference

https://www.howitworksdaily.com/15-amazing-science-facts-that-will-blow-your-mind/