Eight short sentences, each about something a six-year-old knows well: a puppy napping in the sun, a sister on a bike, a bus stopping at school, a frog on a rock. The rule sits right above them (a noun names a person, an animal, a place or a thing) and the child circles every noun they can find.
The instruction says noun or nouns on purpose. Most of the sentences hold two, so a child who circles puppy and moves on has only done half the line. Ben in sentence three is a good one to talk about, because a name is a noun too, and sentence five starts with We, which is not.
It is a good first step from sorting single words into finding nouns inside a sentence, where they sit next to verbs and little words like the and a.