You can use these primary sources anyway you want within a classroom context. You can download these images for use in projects, learning materials and also for other related educational classroom activities.
However we ask that if you use these items you acknowledge the creator of the content you are reusing and also the National Library. You can do this simply by adding the caption (underneath each item) to your work. Or you can put a general acknowledgement at the end of your work, like a bibliography or film credits.