I printed a few pictures off the internet of various animals with more-than-the-usual amount of eyes. Then I gave Nora a big ol' pile of googly craft eyeballs. Her "job" was to decorate the critters however she liked, and then put on the number of eyeballs that each animal has. Together, we counted them.
Here are some animals you can use for this activity.....
Spiders: 2 -8 eyes (most have 8)
Box Jellyfish: 24 eyes
Scallops: can have 100 eyes (okay, don't really make your child glue 100 eyes onto a piece of paper!!) :)
Flies: Actually have 5 eyes -- two huge (relatively speaking) compound eyes and three simple eyes
Giant squid: Two eyes -- the largest eyes on earth!
Crabs: Two eyes
European wasp: Five eyes
Starfish: Most have 5 eyes, one on the end of each arm
My daughter was exactly 4 1/2 when we did this activity. It seemed to be a good level for her. Counting out items above 20 was a good way to help bigger numbers become more concrete. It was a nice little mix of science, math, and art all in one simple activity.