This is a collection of worksheets on 2 digit by 1 digit addition. It has seventeen different types of activities for differentiation, including using a standard algorithm, showing the solution, missing addend or sum, vertical addition, using grid, coloring the correct answer, and adding three numbers. You can use these math worksheets as a review, homework, quiz, pre test, assessment, drill, or fluency practice for your students in the 1st or 2nd grades. *** View our Addition Bundle to save