Sequences organize the world—and our ability to recognize them helps us in everything from math to cracking codes and ciphers. With this slew of sequence-base

Like adding one + one + one, this collection will increase your numerical smarts and boost your mathematical confidence. Start solving with a series of themed c

Did you know that every time you're trying to fit a couch through a doorway or figuring out the right angle to sink the eight ball, you're solving a shape-relat

Marilyn vos Savant—credited by the Guinness Book of World Records with the highest IQ ever recorded—brings you an effective, entertaining program designed t

Provides hundreds of specific brainbuilding exercises designed to stretch and enhance your mind.