H2O Refraction Science
Awesome simple science.
http://www.whatdowedoallday.com/2015/08/water-refraction-science-experiment.html?utm_source=MadMimi&utm_medium=email&utm_content=Easy+Idea+For+Right+Now+With+WOW&utm_campaign=20150813_m126922839_Easy+Idea+For+Right+Now+With+WOW&utm_term=water_refrac_fb_jpg_3F1439390691
'WWDAD" has a great video. I struggled several times before getting this experiment down and have learned to experiment before the experiment, lest the little people lose interest in my farting around to get it right!
The size and shape of the jar, matters greatly!
Also, how far it's placed from the paper; too close and it works like a magnifying glass (you can't make out which is which because it all looks huge!), but too far and you add a few extra images all out of line.
Once you get it right, it's a science crowd-pleaser!