A blackboard (UK English) or chalkboard (US English) is a reuseable writing surface on which text or drawings are made with sticks of calcium sulphate or calcium carbonate, known, when used for this purpose, as chalk. Blackboards were originally made of smooth, thin sheets of black or dark grey slate stone. Modern versions are often green because the color is considered easier on the eyes.
Childhood is the age span ranging from birth to adolescence. Childhood consists of two stages: preoperational stage and concrete operational stage. In developmental psychology, childhood is divided up into the developmental stages of toddlerhood (learning to walk), early childhood (play age), middle childhood (school age), and adolescence (puberty through post-puberty). Various childhood factors could affect a person's attitude formation.
This is the time for children to be in school and at play, to grow strong and confident with the love and encouragement of their family and an extended community of caring adults. In this age children live free from fear, safe from violence and protected from abuse and exploitation. As such, childhood means much more than just the space between birth and the attainment of adulthood. It refers to the state and condition of a child’s life, to the quality of those years.