Hi Ninag0410,

A benchmark in math has the same definition as a benchmark outside of math. TheFreeDictionary.com defines a mathematical benchmark as, "a criterion by which to measure something; standard; reference point". Hope that helps!

Benchmarks at this point are developed into content learning standards at each grade and state. Benchmarks can be found on your local state public school website.
When the ESEA (Elementary and Secondary Education Act) is re-authorized there will be CORE (common National Standards) in which all children/young adults will be college or career ready once completing their K-12 education. I have provided the link to CORE standards as explained by the ISBE (Illinois State Board of Education) below.
What are you interested specifically in understanding about benchmarks in a specific grade? Are you homeschooling?
Erika Burton, Ph.D.
Stepping Stones Together, Founder
http://www.steppingstonestogether.com
http://www.isbe.net/common_core/default.htm