Lesson: Estimating the Sum and Difference of Fractions by Rounding Holt Mathematics • Course 1 • Go Math! • Grade 5 • Common Core • JUMPMath 7.1 • Part 1 of 2 • Assessment & Practice • US Edition • Math Connects • Grade 5 • Student Edition • enVisionmath2.0 • Grade 5 • Volume 1 • Common Core • enVisionmath2.0 • Grade 4 • Volume 2 • Common Core