Final answer:
In middle childhood, a child typically doubles their weight from ages six to eleven, growing steadily at an average of about 7 pounds per year.
Step-by-step explanation:
In middle childhood, a child will typically double his or her weight from ages six to eleven. During this life stage, which covers ages 6 to 10 years, children experience steady growth with an average gain of about 3.2 kg (7 lb.) per year and an increase in height by about 5.8 cm (2.3 inches) per year. It is a period characterized by slow and steady physical development in abilities such as agility, balance, and endurance. Furthermore, children develop stronger muscles, improved coordination, and become more adept at activities such as riding a bicycle.
By around the age of 12, the average child weighs approximately 41 kg (91 lb.), which suggests that from ages six to twelve, there is a substantial gain in weight, reflecting an increase in both muscle mass and the beginning of growth spurts associated with pre-adolescence.
While the exact amount of weight a child will gain can vary widely due to individual differences, such as genetics and lifestyle, the mentioned averages provide a general guideline for expected growth in the stage of middle childhood.