My students really struggled with figuring out whether to add or subtract. I created two posters that have some of the most used words in addition and subtraction problems. We referred to these posters often when completing these practice worksheets. There are two addition worksheets, two subtraction, and then two mixed (using some of the problems on the first four worksheets). At the top of each worksheet is an example of what their work should look like as a reminder. These are great for practice after the concepts have been taught or for homework!