Are your K-4th graders familiar with silver dollars? I'm trying to come up with an analogy for the size of a young horseshoe crab (about 1.5 inches in diameter, plus a tail). A scientist suggested I use a silver dollar as a comparison, but I'm not sure if that's a good choice, since it seems like many children might not have seen them. This is for a book, so I can't just hold one up to show them.
Other possibilities--lollipop? (possibly too much variation in size, but very familiar)? Car key? Plastic soup spoon? Any enthusiasm or other suggestions welcome!
Lisa