Final answer:
The brain of a child reaches 70% of its adult size around 6 years old. In early childhood, the frontal lobes grow rapidly, allowing children to control their attention and behavior. All lobes of the brain continue to grow throughout the elementary school years.
Step-by-step explanation:
The brain of a child reaches 70% of its adult size around 6 years old. In early childhood (ages 3-6), the frontal lobes, which are associated with planning, reasoning, memory, and impulse control, grow rapidly. By the time children reach school age, they are developmentally capable of controlling their attention and behavior. Throughout the elementary school years, all lobes of the brain continue to grow in size, contributing to cognitive advances.