On Monday, he ate through 1 apple but he was still hungry!

On Tuesday, he ate through 2 pears but he was still hungry!

On Wednesday, he ate through 3 plums but he was still hungry!

On Thursday, he ate through 4 strawberries but he was still hungry!

On Friday, he ate through 5 oranges but he was still hungry!

The Very Hungry Caterpillar book eats through a whole bunch of fruits in a little less than a week. Yep—that's basically the entire story.

A caterpillar eating fruits? Doesn't seem like much to us. But the focus on actions and basic needs (see: hunger) appeal to kids. They know what it means to be hungry—and they also know how to scream their diapers off when they feel that sensation.

In five simple lines, Eric Carle teaches children

• the days of the week (5 of 'em, at least).
• the numbers 1 through 5.
• the names of 5 different fruits.

Of course, kids won't read/hear these words and suddenly know them forever (if only). But kids do love to read the same books over and over, and eventually it sinks in. Children's literature helps kids understand their immediate surroundings, and while caterpillars may not be eating fruit in their homes, they do hear days of the week, numbers, and food names all the time.

P.S. Notice that there's a lot of repetition, but there's also variation (in the numbers and the days of the week), which helps kids see the bigger picture.