1. Your Body puzzle
$24.95 at fatbraintoys.com; ages 4 and up
A five-layer birch puzzle lets kids peer inside the human body, revealing the digestive tract, nerves and skeleton. Katy Shepard, a Ph.D. candidate in neuroscience at Emory University, says her three-year-old cousin received this puzzle after he pointed to his skin and asked, “What comes next?”

2. Life Cycle Stacking Blocks
$19.95 at forsmallhands.com; ages 2 to 6
Paperboard boxes that stack nearly three feet high and feature beautiful illustrations of the life cycles of the butterfly and frog are accompanied by an informative poem, says Julie Frey, a fifth grade teacher at Stuard Elementary School in Aledo, Tex.

3. Skull puzzle
$23 at theevolutionstore.com; ages 8 and up
This 39-piece 3-D puzzle comes with a removable brain. “This puzzle is educational, challenging and, most important, fun,” says Kent Kirshenbaum, a chemistry professor at New York University. “Bonus: the jaw swings open and shut hauntingly after you complete it.”

4. Bones: Skeletons and How They Work
by Steve Jenkins (Scholastic, 2010); ages 7 and up
Michelle Nijhuis, a biologist and author, recommended this book and the two following ones. (For more of her suggestions, go to lastwordonnothing.com.) Bones, she writes, has fantastic illustrations and “is also great for inspiring hands-on research.”

5. Far from Shore: Chronicles of an Open Ocean Voyage
by Sophie Webb (Houghton Mifflin, 2011); ages 9 to 12
This book chronicles the author’s four-month-long Pacific research voyage. “Webb describes her work in some depth, but she emphasizes not the results but the experience: the starlit nights on deck, the sightings of dolphins and whales and seabirds, and daily life with her fellow scientists,” Nijhuis writes.

6. Tuesday
by David Wiesner (Clarion, 1997); ages 5 to 8
“Late one Tuesday evening a mob of frogs flies through town on lily pads, disappearing as quickly as it came. Why? This almost wordless story doesn’t say, leaving kids free to form their own theories about spontaneous frog flight,” Nijhuis says.

7. Evolution: How We and All Living Things Came to Be
by Daniel Loxton (2010); $18.95 at kidscanpress.com; ages 8 to 13
Eugenie Scott, executive director of the National Center for Science Education, touts this book as “an excellent introduction to a topic not frequently covered in children’s books. There’s more to evolution than dinosaurs, after all!”

8. Magic Briks bristle blocks
$26.95 at kaplanco.com; ages 3 and up
Never underestimate simple building blocks. Noah Cowan, an associate professor at Johns Hopkins University’s Whiting School of Engineering, says they are “an essential component in developing a child’s ability to reason about space, time and even challenging concepts like entropy. Bristle blocks are particularly good for young children who don’t yet have the dexterity for Legos—and, frankly, bristle blocks are even more open-ended because the connector density is higher.”

9. Shark in a Jar—Squalus acanthias
$29 at theevolutionstore.com
This real baby shark taken from an adult caught by a commercial fisher “offers a launching point for discussions about the differences between sharks and bony fish, the diverse ways sharks bear their young, and the importance of conservation for threatened shark species,” N.Y.U.’s Kirshenbaum says.

10. Science kits
from Thames & Kosmos
From $13.95 at thamesandkosmos.com; ages 5 and up
Christof Koch, a professor of cognitive and behavioral biology at the California Institute of Technology, grew up playing with these designer sets, many made by a 189-year-old German company. “These days kids see computer simulations and watch YouTube but don’t do that much with their own hands anymore,” he says. More than 60 different kits are available for various ages and specialties—from chemistry and biology to energy and forensics.

11. Non-Stop Top with Built-in Light Show
$14.99 at amazon.com
This battery-powered top has a motor with an eccentric weight inside that keeps it spinning until the battery runs out. Matt Moses, who just earned his Ph.D. in mechanical engineering at Johns Hopkins, asks these questions when showing it to students:

  1. "Would the top work if you spun it on a frictionless surface?
  2. "Suppose you were in orbit inside the International Space Station. If you spun it in midair, would it still work?
  3. "If the weight inside were not eccentric—that is, if it were perfectly balanced on the motor—would the top still work?
  4. "Does the weight spin in the same direction the top is spinning in or in the opposite direction?”

12. Giant Microbes
From $8.95 at giantmicrobes.com
These fuzzy replicas of human cells, viruses and bacteria include the common cold (rhinovirus), neurons, and red and white blood cells. “The large size and kid-friendly plush help students visualize microscopic structures,” says Emory’s Shepard.