Math Progressions

Narratives describing the progression of math topics throughout the grades:
http://ime.math.arizona.edu/progressions/

Math Model Curriculum

The Ohio DOE has created model curriculum for each grade level. Here are links to 3rd and 4th grade:

http://education.ohio.gov/getattachment/Topics/Academic-Content-Standards/Mathematics/Grade-3-Model-Curriculum-for-Mathematics-pdf-1.pdf.aspx

http://education.ohio.gov/getattachment/Topics/Academic-Content-Standards/Mathematics/Grade-4-Model-Curriculum-for-Mathematics-pdf-2.pdf.aspx

And the general resource website (with these links):

http://education.ohio.gov/Topics/Academic-Content-Standards/Mathematics

CCSS Math Curriculum Maps

CCSS Toolbox has sequenced units for all grade levels aligned to the Core.

http://www.ccsstoolbox.com/