reading level of captain underpants

From Caterpillar to Butterfly - (Let's-Read-And-Find-Out Science 1) by Deborah Heiligman (Paperback)

Where Are the Night Animals? - (Let's-Read-And-Find-Out Science 1) by Mary Ann Fraser (Paperback)

Sounds All Around - (Let's-Read-And-Find-Out Science 1) by Wendy Pfeffer (Paperback)

How Deep Is the Ocean? - (Let's-Read-And-Find-Out Science 2) by Kathleen Weidner Zoehfeld (Paperback)

Ty's Travels: All Aboard! - (My First I Can Read) by Kelly Starling Lyons

Just a Special Day - (My First I Can Read) by Mercer Mayer (Paperback)

Pete at the Beach - (My First I Can Read) by James Dean & Kimberly Dean (Hardcover)

Pete the Cat and the Lost Tooth - (My First I Can Read) by James Dean & Kimberly Dean (Hardcover)

Sunshine Makes the Seasons - (Let's-Read-And-Find-Out Science 2) by Franklyn M Branley (Paperback)

Animals in Winter - (Let's-Read-And-Find-Out Science 1) by Henrietta Bancroft & Richard G Van Gelder (Paperback)

What's for Lunch? - (Let's-Read-And-Find-Out Science 1) by Sarah L Thomson (Paperback)

The Moon Seems to Change - (Let's-Read-And-Find-Out Science 2) by Franklyn M Branley (Paperback)

Ty's Travels: A 5-Book Reading Collection - (My First I Can Read) by Kelly Starling Lyons (Paperback)

Ty's Travels: Super Ty! - (My First I Can Read) by Kelly Starling Lyons

Pete the Kitty Goes to the Doctor - (My First I Can Read) by James Dean & Kimberly Dean (Hardcover)

Little Critter: This Is My Town - (My First I Can Read) by Mercer Mayer (Paperback)

Biscuit Wins a Prize - (My First I Can Read) by Alyssa Satin Capucilli (Paperback)

What Will the Weather Be? - (Let's-Read-And-Find-Out Science 2) by Lynda DeWitt (Paperback)

Duck, Duck, Dinosaur: Perfect Pumpkin - (My First I Can Read) by Kallie George (Paperback)

Ty's Travels: Beach Day! - (My First I Can Read) by Kelly Starling Lyons

Running on Sunshine - (Let's-Read-And-Find-Out Science 2) by Carolyn Cinami Decristofano (Paperback)

How Many Teeth? - (Let's-Read-And-Find-Out Science 1) by Paul Showers (Paperback)

Fossils Tell of Long Ago - (Let's-Read-And-Find-Out Science 2) by Aliki (Paperback)

Ty's Travels: Zip, Zoom! - (My First I Can Read) by Kelly Starling Lyons