This resource includes a PDF and Powerpoint version. This is a strategy I use to teach my students how to find elapsed time using an open number line. The strategy uses "mountains and hills" to represent hours and minutes. I've included the steps in setting up your number line, as well as 2 examples. One example walks you through finding the elapsed time and the other example walks you through finding the ending time. I've also included 2 practice word problems with an answer key.
The Powerpoint version is great for introducing the strategy to your class, as it walks you through step by step. That allows students to easily copy and follow along!