This is a Smartboard lesson that allows students to practice solving word problems involving subtracting. All of the numbers are 20 or less. Each difference is given and students need to solve for the missing subtrahend. Subtrahend is the number being subtracted. Each page asks students to come up with the correct number sentence and then to figure out the answer. Both of these are provided on each page. The preview file has thumbnail shots of many of the pages in this lesson. The last page can be used for guided practice without the word problems. I also have a file in my store with subtraction word problems where students need to figure out the difference.