Do your students need help practicing Operations and Algebraic Thinking? This reproducible worksheet packet includes 25 different worksheets designed to practice the Common Core State Standards 1.OA.2, 1.OA.2, 1.OA.B.4, 1.OA.6, and 1.OA.D.7. Great for morning work, independent math practice, or fast finishers! Includes activities such as addition and subtraction facts to 20, unknown numbers for addition and subtraction, meaning of the equal sign, and word problems (addition/subtraction/3 addends