Only if your class needs them. Warm Up items are designed to allow your students to review the skills they will need for the Lesson. You can choose to use none, some, or all of the Warm Up items based on how your students perform on the Assess Readiness and/or your own knowledge of their needs. If students need additional review before they are ready for the Focus items, then you can use Warm Up to get them up to speed. Each Warm Up item is tagged with its corresponding prerequisite standard(s).