Subscribe to Scientific American to learn and share the most exciting discoveries, innovations and ideas shaping our world today.

Free online access to Grade 1 Go Math! textbook, including glossary and correlations.

To form a bagel, the Carbohydrate Bakeshop starts with a spherical wad of dough. The spherical wad of dough has an area of 525.8947391 square centimeters. The sphere is reformed into a perfect torus, ...

Can you chip in? This year we’ve reached an extraordinary milestone: 1 trillion web pages preserved on the Wayback Machine. This makes us the largest public repository of internet history ever ...

You and I are sitting at a table with a pile of 50 quarters and an empty piggy bank. We will take turns placing anywhere from one to 10 quarters in the bank at a time. Whoever places the last quarter ...

Popular Puzzle Game Now Free Forever After Dev Forgot About This Steam Rule The developer behind Pico Park: Classic Edition made the game free over the summer as he worked on updates. But he got a ...

The NYT Brain Tickler is a uniquely challenging and entertaining puzzle from The New York Times that forces your brain beyond just the ordinary logic game. Each Brain Tickler presents a new style of ...

The PC version of a well-received co-op puzzle game has been made free forever by accident, after it was updated with online functionality. Between subscription services like PS Plus and random ...

One developer’s mistake has accidentally made a great game permanently free on Steam. Fortunately for developer Tecopark, the mix-up affects a nearly 10-year-old title that was already cheap, and that ...