K-5 (pronounced "kay through five") is an American term for the education period from kindergarten to fifth grade. It receives equal amounts of criticism and support in the educational industry. While many early childhood experts deem it too closely aligned with more developmentally inappropriate "watered-down" early elementary teaching methods, administrators and policy-makers see at as way to integrate kindergarten under the guise of the No Child Left Behind Act of 2001.
According to National Association for the Education of Young Children, early childhood spans the human life from birth to age 8. (Wiki article entitled Early Childhood) Most people think of early childhood as ending by the end of Kindergarten, usually age six. The comment above about early elementary teaching methods being "inappropriate" and "watered-down" needs some serious citations. In different parts of the country, education is going to be different. Although the majority of schools have agreed to follow NCLB, there are still different standards to comply with depending on the school, county, district, state, etc. Most people think of Kindergarten as the following "Kindergarten (help·info) (German, literally means "children's garden") is a form of education for young children which serves as a transition from home to the commencement of more formal schooling. Children are taught to develop basic skills through creative play and social interaction." (Wiki article entitled Kindergarten) However, this is not always the case.
In Montgomery County Maryland, they have developed the "Seven Keys for College Readiness" which is include students reading above grade level in grades Kindergarten through Second. This county believes that by starting with high standards in the early childhood grades, it will be easier for these children to have success down the road in higher education.(http://www.montgomeryschoolsmd.org/info/keys/) As one might imagine, it is not an easy feat to have five year old children reading by the end of the school year when they come in not knowing any letters or letter sounds. It certainly would not be attainable by using "inappropriate" and "watered-down" teaching methods. It is a high standard but one that Montgomery County Public School teachers are ready and eager to meet.
In the state of California, there are high expectations as well. In math, Kindergarten students are learning things like geometry, algebra, measurement, and data analysis. Students are expected to "Pose information questions; collect data; and record the results using objects, pictures and picture graphs" and "Make precise calculations and check the validity of the results in the context of the problem." (http://score.kings.k12.ca.us/standards/kdg.html)
Sarah Irvine Belson, professor and author of the book Technology for Exceptional Learners says "To succeed in school, all children must enter Kindergarten with basic skills and beginning literacy." (page 243) This does not happen for every child everywhere in the country. To help children who may not be getting these basic skills before starting Kindergarten, there is Head Start. "Substantial research finds that Head Start and Early Head Start programs provide positive educational benefits. Recent Head Start Family and Children Experience Survey (FACES) data shows that HS graduates, by the spring of their kindergarten year, were essentially at national norms in early reading and early writing and were close to meeting national norms in early math and vocabulary knowledge." (http://www.nhsa.org/files/static_page_files/A97D0E16-1D09-3519-AD6A427CB89EA478/08FactSheetHSWorks.pdf)
Harry Wong and Rosemary Wong, authors of the book "How to be an Effective Teacher: The First Days of School" say in chapter seven, page 45, "The most important day of a person's education is the First Day of School, not Graduation Day."