elementary school

Short definition from Wiktionary

Noun

1. 1
   A children’s school, typically older than toddlers and younger than adolescents. In the U.S., elementary schools cover grades 1 through 5, and the ages of the children are usually 6-11 years. At a minimum, elementary schools will teach basic reading, writing, arithmetic, and history.
2. 2
   A primary education school for grades 1-6 (a continuation of preschool). It is succeeded by junior high school.