Finding free copyright-free images to use in the classroom isn't always easy. This page shares some ways to find free images to use and some sites that provide free, copyright-free images. Some require attribution.
Free Source Collections
Creative Commons Search - Enables you to choose a library to search eg. Flickr or Google Images by selecting a CC usage licence.
Google Research Tool - you can search directly from Google Docs or Slides. Click Tools > Research>Images and then the little drop down arrow to choose usage rights. Drag image to document. Automatic citation.
Google Search - usage rights. Enter the search term, Click Enter then select images and then select Usage rights.