An educational resource that began its life as "AbiClipart" in 2003. The collection is a safe way for children to search for images for use in school projects. Of course, other folks also find plenty of uses for the clip art and photos.
"Need a pentagonal pyramid that's six inches tall? Or a number line that goes from ‑18 to 32 by 5's? Or a set of pattern blocks where all shapes have one-inch sides? You can create all those things and more with the Dynamic Paper tool. Place the images you want, then export it as a PDF activity sheet for your students or as a JPEG image for use in other applications or on the web."