Final answer:
Preschool children, aged 3 to 6, usually gain around 4 to 6 pounds and grow 2 to 3 inches in height each year.
Step-by-step explanation:
During the preschool years, which include ages 3 through 6, the average weight gain per year for children slows down compared to their earlier years.
Preschoolers typically gain about 1.8 to 2.7 kg (4 to 6 lbs) per year and grow approximately 5.1 to 7.6 cm (2 to 3 inches) in height each year. This period of slowed growth continues until they approach pre-adolescence when some children may start experiencing the adolescent growth spurt.