Your students will use these activity sheets to master addition and subtraction. Each sheet contains a number of different equations for your students to solve. Activities include using pictures as counting tokens and filling in the blanks in equations to make them correct. All equations are based on the numbers four and five, either as part of the equation or as the final answer. Answer keys have been provided for each activity sheet for instructors. Note for Instructors: If you cannot use these worksheets in your regular curriculum, they make great review pieces or extra credit assignments for your students.