Grade 4

Why does the wind blow? What does air pressure have to do with a thunderstorm? Why is a mountaintop snowy while the valley below is warm? The answers to these questions all involve the… Read More →

Josh and Danny are stuck in Princess Land—a store full of pink toys and worse: actual girls! To avoid security guards and screeching girls, the twins try a quick spritz of the infamous… Read More →

Have you ever solved a tricky puzzle? As kids, Joanna Kelley and her siblings had fun solving the math and science challenges their parents invented at the dinner table. Later, Kelly's love… Read More →

Printing words in books originated in China with the invention of movable type. But books aren't the only way we've communicated throughout history. Find out who invented the first radio,… Read More →

Tin cans were first produced in London in 1813. But they had to be opened with a hammer and chisel, because the can opener wasn't invented until 1855! Check out other amazing engineering… Read More →

Before magnifying glasses, how did people make objects look larger? The ancient Romans filled glass bowls with water. Then microscopes and telescopes came along. But optical innovation didn't Read More →

Have you ever used your imagination to solve a problem? When Albert Einstein was young, he was fascinated by the way magnetism made a compass work. As an adult, he used thought experiments to Read More →

Bicycles were only invented about two hundred years ago—and the first ones didn't have tires or brakes! But bikes aren't the only way we've tried to conquer the roads, seas, and skies. You'll Read More →

Math Lab for Kids proves that math is more than just numbers—the hands-on activities in this book make learning math fun! In Geometry and Topology, kids learn to think about shapes in new… Read More →

George Frideric Handel (1685–1759), a German-born Baroque composer, achieved international acclaim for his operas, oratorios, and instrumental compositions. Notable works include Messiah and Read More →

George Morrison, a skilled Ojibwe artist, grew up on the shores of Lake Superior, and by the age of nine was known for his drawing and creative talents. He graduated from the Minneapolis… Read More →

You know that a joke is a funny story that makes people laugh. A practical joke is different - it is a trick that is meant to be funny, but sometimes it is not very funny for the person who… Read More →

Late in the spring of 1787, fifty-five men gathered at the Pennsylvania State House. They came to write a new constitution for the United States. The leader of this Constitutional Convention… Read More →

Born a slave near the end of the Civil War, George Washington Carver was a small and sickly child. Too frail to work in the fields of the Missouri farm where he grew up, George did chores… Read More →

Pack your bags! We’re headed to Germany. On this whirlwind tour, you’ll learn all about the country’s landscape, culture, people, and more. We’ll explore Germany’s Bavarian Alps, visit the… Read More →

Growing up in the 1830s, Louis Pasteur saw the horrifying effects of diseases like rabies and tuberculosis. Filled with curiosity and imagination, Pasteur began a lifelong search for answers… Read More →

Look out—this book is FULL of germs! Have you ever seen a germ up close? Really, really close? Zoom in on a variety of viruses, bacteria, protozoa, and fungi that can make people… Read More →

Most substances on Earth are mixtures of different molecules. The way these molecules react to each other causes all sorts of everyday mixtures and solutions, from butter to plastic to soap!… Read More →

What does it mean to be elected to political office? It means you get to decide how to make a town, a state, or even the whole country a better place to live. But how does someone get… Read More →

How many places do people go in a day? People are always on the go between school, work, shopping, and activities. But how we go can be just as important as where we go. Learn about different Read More →