Try out these "number magic" tricks―from counting techniques to mathematical shortcuts―as well as logical thinking challenges that test the left side of your brain.
Sometimes your eyes can fool your brain. But with training, your brain can outsmart your eyes to find out what's really going on. Check out these optical illusions and other visual puzzles.
Shapes can be surprising, whether they're forming images you never expected or they're hiding in plain sight. Train your brain to be a shape-puzzle expert with this book.