Rational numbers: Absolute values, opposites, plotting points, converting rational numbers from fractions to decimals, reflections on a coordinate plane (x-y plane), and using absolute value expressions to find distances between two rational points on an x-y plane. All of these things are part of sixth grade current and future Common Core Math Standards. THE BAD NEWS: The standards for sixth grade instruct the teacher to merely scratch the surface of rational numbers (opposite, absolute value, e