This document provides 40 different ways that QR codes can be used in the classroom. Some examples include using QR codes to provide access to online resources, videos, or websites related to topics in textbooks or assignments; creating scavenger hunts or games using QR codes placed around the school; and adding QR codes to displays, posters, or other materials around the school to provide interactive or additional digital content. The document also provides tips for generating QR codes and tools for reading them on mobile devices and computers.