Student Achievement Partners
Illustrative Mathematics: Addition and Subtraction Fluency Set of Tasks [Pdf]
Students explore the relationship between addition and subtraction and develop an understanding of decomposing numbers in different ways in this first-grade lesson plan.
Illustrative Mathematics
Illustrative Mathematics: F Tf Sum and Difference Angle Formulas
The goal of this task is to have students derive the addition and subtraction formulas for cosine and tangent, and the subtraction formula for cosine, from the sum formula for sine. Aligns with F-TF.C.9.
Illustrative Mathematics
Illustrative Mathematics: 1.oa Using Lengths to Represent Equality
In this lesson plan, 1st graders determine if lengths are equal to one another.