The image that you see to above was used in a blog post that I wrote years ago. It recently surfaced again when I was looking for an old math resource (sadly, no longer available). 

The image above was made by blending two images together in Google Slides. To make the final image I went to Pixabay and grabbed a public domain image of a beach and a public domain image of an abacus. Then in Google Slides I used the image editing tools to layer the images and adjust the transparency so that it looks like the abacus and beach are blended together. Watch the video embedded below to see how I did it (email and RSS readers, you’ll have to click through to the blog to see the video).