Use this Smartboard Lesson to help teach your students how to add three numbers together. You can use this lesson in one day or over a span of a couple days. Not only does this Smartboard lesson offer great tools and tips on how to add three numbers together - it also provides many different practice opportunities. This Smartboard lesson also covers story problems that involve adding three numbers together. This is a great lesson to use year after year or also as a quick and easy lesson to leave for a substitute!