Illustrative Mathematics (IM) in partnership with Open Up Resources have fully-developed an outstanding, free, high-quality Mathematics OER core-curriculum for school districts. IM is completely OER-based, Common Core Standards aligned with current C & I scope and sequence requirements satisfied for teaching mathematics grades 6-8. IM is a problem-based core mathematics curriculum grades 6-8 that develops student's mathematical skills through questioning, discussion, and real-world contexts and connections. Note: IM is currently developing OER-based curriculum for high school Algebra I, Geometry, and Alegebra II that will coincide with IM 6-8 program. Districts interested in using IM 6-8 can visit im.openupresources.org .