The summer slide is also known as summer learning loss. Skills and knowledge acquired over the last academic year don't simply stand still while your child takes a break from school; in fact, they erode.
Between the end of one school year and the beginning of the next, children can easily lose progress they made over the past year. This problem is especially pronounced in children who come from low-income households, the reason being a lack of resources. The learning gap between social classes widens much faster during the summer than during the school year. However, most children show some form of summer learning loss when they return for the next school year.
Teachers across all subjects usually spend about six weeks each school year reteaching students the material learned the year before in order to prepare students to learn new things. As a result, students often lose a little more than two and a half months' worth of math skills and two months of reading skills.
Each summer, some students fall farther and farther behind. By the end of sixth grade, students who have repeatedly experienced summer learning loss can be about two years behind.