When you were a baby, you didn't have any teeth at all. Then as you grew, your teeth started to come in. First one, then two - and finally, twenty teeth in all!

But you won't keep these teeth forever. First one, then two, will wiggle loose. Maybe you've lost some of your first teeth already. When the little teeth come out and the big teeth come in, everyone can see - you're growing up.

Paul Showers has written
many of the Let's-Read-and-Find-Out-Science series' most popular titles, among them Where Does the Garbage Go?, illustrated by Randy Chewning. Mr. Showers lives in Palo Alto, CA.

Wendy Watson has illustrated numerous classic picture books, including A, B, C, D, Tummy, Toes, Hands, Knees by B. J. Hennessey. Ms. Watson lives in Groton, VT.