Vygotsky's theories are easily applicable in elementary school. Think, for example, of the "zone of proximate development (ZPD)." A child who is not yet able to identify symbols as representing sounds cannot be moved on to the idea that these symbols will combine into words. That is simply too big a stretch. However, the child who understands that symbols stand for sounds is ready for the next stage, which is combing those symbols and sounds into words. Similarly, the child who understands that numbers represented quantities is in the ZPD in which he or she may, with assistance, begin to learn that one can add or subtract quantities with the use of numeric symbols. All learning must connect to something that is already present in the brain, and the idea is that trying to teach a child who does not possess a sufficient foundation will end in frustration and mostly failure. Simply put, Vygotsky's ZPD could be characterized as "baby steps." Elementary school teachers put this theory into practice in all content areas. What kinds of examples can you think of in science, art, or physical education? A child who has an understanding of the solar system can now grasp the concept of the rotation of the earth. A child who can draw two-dimensionally might be ready to learn to draw in three dimensions. The child who knows how to swing at a ball with hands should be able to learn to connect with the ball with an extension such as a bat or racket.