Math - Ratio and Proportion by Caroline Witt - Wednesday, 2 May 2012, 2:37 PM Number of replies: 0 NCTM Illuminations is always Common Core Friendly! Examples: http://illuminations.nctm.org/ActivityDetail.aspx?ID=178 http://illuminations.nctm.org/LessonDetail.aspx?ID=L510 Permalink Reply