I wanted the same thing for my kids. So, I got to work and created a couple of pinhole viewers from wrapping paper tubes, tin foil, tape, and a pin.
The kids loved it. Surprisingly Emm a lot more than Jothan. He took one look and was pretty much done, Emm tried every little trick to see the eclipse from the pinhole viewer to making tiny pinholes with her hands, and we even caught a glimpse of it through Camilla's dress. We can hear her saying, "See mine smiley face?" "Oh it's a smiley face!" My only regret was not having a macro lens to get a little bit closer to the actual image of the sun.
Such a fun evening, one we won't forget anytime soon.
All shot on a Nikon N80, 50mm 1.4 lens on Kodak Portra 400