April 1

Can You See What I See?: Treasure Ship by Walter Wick (Scholastic/Cartwheel, $13.99; ISBN 978-0-439-02643-7). 150,000 copies.

April 6

The 39 Clues: The Emperor's Code by Gordon Korman (Scholastic, $12.99; ISBN 978-0-545-06048-6). 500,000 copies.

Night World #10: Strange Fate by L.J. Smith (Simon Pulse, $18.99; ISBN 978-1-4169-8677-5). 400,000 copies.

The Reckoning by Kelley Armstrong (HarperCollins, $17.99; ISBN 978-0-06-166283-6). 250,000 copies.

Alphas #2: Movers and Fakers

by Lisi Harrison (Little, Brown/Poppy, $9.99 paper; ISBN 978-0-316-03580-4). 200,000 copies.

We the Children: Keepers of the School by Andrew Clements (S&S/Atheneum, $14.99; ISBN 978-1-4169-3886-6). 100,000 copies.

April 9

Iron Man 2: The Junior Novel by Alexander Irvine (LB Kids, $5.99 paper; ISBN 978-0-316-08354-6). 150,000 copies.

April 13

Prince of Persia: Junior Novel (Disney Press, $5.99 paper; ISBN 978-1-4231-1780-3). 350,000 copies.

Decide Your Destiny: Prince of Persia: The Guardian's Path (Disney Press, $4.99 paper; ISBN 978-1-4231-2700-0). 200,000 copies.

Decide Your Destiny: Prince of Persia: To Right a Wrong (Disney Press, $4.99 paper; ISBN 978-1-4231-1796-4). 200,000 copies.

Prince of Persia: Before the Sandstorm by Jordan Mechner (Disney Press, $9.99 paper; ISBN 978-1-4231-2582-2). 150,000 copies.

Rules of Attraction: A Perfect Chemistry Novel by Simone Elkeles (Walker, $16.99; ISBN 978-0-8027-2085-6). 125,000 copies.

April 20

Radiant Shadows by Melissa Marr (HarperCollins, $16.99; ISBN 978-0-06-165922-5). 150,000 copies.

April 21

The Very Fairy Princess by Julie Andrews and Emma Walton Hamilton, illus. by Christine Davenier (Little, Brown, $16.99; ISBN 978-0-316-04050-1). 100,000 copies.

The Daughters by Joanna Philbin (Little, Brown/Poppy, $16.99; ISBN 978-0-316-04900-9). 100,000 copies.

April 27

The Carrie Diaries by Candace Bushnell (HarperCollins/Balzer + Bray, $18.99; ISBN 978-0-06-172891-4). 500,000 copies.

Kingdom Keepers III by Ridley Pearson (Disney-Hyperion, $17.99; ISBN 978-1-4231-2899-1). 150,000 copies.

What's Your Sound, Hound the Hound? by Mo Willems (HarperCollins/Balzer + Bray, $10.99; ISBN 978-0-06-172844-0). 150,000 copies.

The Sandwich Swap by Rania Al Abdullah and Kelly DiPucchio, illus. by Tricia Tusa (Disney-Hyperion, $16.99; ISBN 978-1-4231-2484-9). 100,000 copies.

As Easy as Falling Off the Face of the Earth by Lynne Rae Perkins (Greenwillow, $16.99; ISBN 978-0-06-187090-3). 100,000 copies.

Instructions by Neil Gaiman, illus. by Charles Vess (HarperCollins, $14.99; ISBN 978-0-06-196030-7). 100,000 copies.

The Magic Tree House Activity Book by Mary Pope Osborne, illus. by Sal Murdocca (Random, $5.99 paper; ISBN 978-0-375-86216-8). 100,000 copies.

Olivia Meets Olivia by Ellie O'Ryan (Simon Spotlight, $6.99; ISBN 978-1-4169-9542-5). 100,000 copies.

April 28

Dewey the Library Cat: A True Story by Vicki Myron and Bret Witter (Little, Brown, $15.99; ISBN 978-0-316-03580-4). 150,000 copies.

April 30

The Sisters Grimm: The Inside Story by Michael Buckley (Abrams/Amulet, $15.95; ISBN 978-0-8109-8430-1). 100,000 copies.