Unit 2: Rational Numbers & Length

The big ideas for unit 2 are Ordering & Absolute Value along with Problem Solving in the Coordinate Plane.  The latter can be embedded with the supporting idea of Drawing Polygons in the Coordinate Plane or vice versa as 6.G.3 is an application of 6.NS.8. Time permitting, Positives, Negatives & Zero: Direction & Value in Real-world Contexts and Rational Numbers on the Numberline & the Coordinate Plane can be explored more in depth; although, students should get the gist by focusing just on the big ideas. The key to this unit is to explore length before moving on to area, surface area and volume in the next unit. Length is explored through finding the absolute value between two points on a number line or coordinate plane.  The supporting idea of finding the length of a side of a polygon can be the context to do some of this work. An understanding of the meaning of a linear algebraic term can be understood by working with equivalent linear expressions; for example, y+y+y and 3y for the perimeter of a triangle, which can then be evaluated after being given a rational side length. While students do not go on to solve algebraic equations in this unit, they do explore numerical expressions, equations, and especially inequalities as they explore rational numbers and their placement on the numberline.

The purpose of this unit is to reengage fraction & decimal concepts conceptually by representing them as length.  It is also a chance to build conceptual understanding of linear terms, a small part of Target E.  For example, have students each draw different equilateral triangles, then represent the perimeter of the triangles as y+y+y = 3y (6.EE.3 & 6.EE.4)