For teacher in a hurry, you can have lesson plans that are already scripted for you with worksheets for your students. This no-prep cuboid lesson plan is so easy to follow and it has everything you will need in order to execute a thorough introductory lesson about rectangular prisms/cuboids. It follows the 5E lesson plan template and has a worksheet at the end. It is suitable for grades 3-5 because of the previous knowledge listed in the lesson and the new terms that will be introduced. It is created as a manual for teachers (especially new teachers) to follow with very clear steps. It is available here at my TpT collection.