Early Childhood Development: Physical Growth

Newborns typically weigh around 3.4 kg and measure 40-50 cm in length, with boys being slightly longer and heavier than girls.
In the first few days, newborns lose up to 10% of their birth weight, but regain it by around day 14.
Newborns respond to sounds, turn towards voices, and sleep for up to 18 hours a day.
Newborns are sensitive to pain and prefer sweet tastes, with well-developed hearing and less developed vision.

At birth, children have around 100 billion neurons, which form connections at an incredible rate of 1,000 trillion connections by age 3.
By age 2, the brain is already 80% of its adult size, and by age 6, it reaches 90% of its adult size.
The cerebral cortex continues growing until around age 10, after which the brain starts to shrink in some areas, leading to more efficient brain function but poorer judgment and decision-making in teenagers.

Gross motor skills include whole-body movements, such as walking, running, and jumping, whereas fine motor skills require coordination between small muscles, like those in the hands and fingers.
One-year-olds can bang objects together, put objects in a container, take objects out, and voluntarily let go of objects.
Two-year-olds can scribble, turn over a container to pour out contents, and build a tower of four blocks or more.
Three-year-olds can make circular lines with a pencil, turn book pages one at a time, and build a tower of more than six blocks.
Four-year-olds can copy square shapes, draw a person with two to four body parts, and use scissors.
Five-year-olds can copy triangles and other shapes, draw a person with a body, and begin to copy some capital letters.
Six-year-olds have very good pencil control, writing becomes more adult-like, and they can draw well.

Two-year-olds can walk alone, pull toys while walking, carry large toys, and kick a ball.
Three-year-olds can climb well, walk up and down stairs, kick a ball, and pedal a tricycle.
Four-year-olds can hop and stand on one foot for up to five seconds, go upstairs and downstairs without support, kick a ball forward, and catch a bounced ball most of the time.
Five-year-olds can stand on one foot for 10 seconds or longer, swing, and may be able to skip.
Six-year-olds are constantly active, coordinate their bodies well, and are successful in bat and ball games.

Teeth form before birth in the gums, and the first teeth emerge around 5-9 months.
By 24 months, children typically have around 20 teeth, and by age 6, they begin to lose their first teeth as the second ones come through.

Between 3 to 6/7 years old, children's physical growth slows down, with an average gain of 2-3 inches per year and 5 pounds per year.
Body proportions change, with the body and legs growing longer and the stomach flattening.
Between 6/7 to 12 years old, the average 7-year-old measures around 49 inches (1.24m) and weighs 55 pounds (25kg), while the average 11-year-old measures around 58 inches (1.47m) and weighs 80 pounds (36kg).