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Education.com: k.oa.a.1 Worksheets
[Free Registration/Login Required] Choose from a variety of worksheets which help students practice addition and subtraction with objects, fingers, mental images, and drawings.
Khan Academy
Khan Academy: Add and Subtract Fractions: Word Problems
In this exercise, students practice adding and subtracting fractions with unlike denominators word problems. Students receive immediate feedback and have the opportunity to get hints and try questions repeatedly.