Final answer:
The average child has 20 deciduous teeth, which begin to appear around 6 months of age. These baby teeth are later replaced by 32 permanent teeth starting from around age 6.
Step-by-step explanation:
The average child has a set of 20 deciduous teeth, also known as baby teeth. These teeth typically begin to appear at about 6 months of age. As children grow, these baby teeth are replaced by a full set of 32 permanent teeth. This process usually starts around age 6 and continues until around age 12. Following the emergence of the central incisors, the lateral incisors, cuspid or canines, and molars appear in sequence. By the time a child reaches middle childhood, they would have most of their permanent teeth, with the exception of the third molars, or wisdom teeth, which emerge later in adolescence or early adulthood.