Mensa Exercise Your Mind Math & Logic Puzzles

An old favorite--Mensa Math & Logic Puzzles--gets a brand-new look: it's now in color!
And the puzzles are fantastic: they're the kind of challenge found at the World Puzzle Championships, and they require no language to solve. For example, you are given a grid of dots that has some numbers (0, 1, 2, or 3) in them. You need to connect the dots in one continuous path so that each number is surrounded by that many lines. So a "3" means that three of the four sides around it must be connected. All the puzzles are similar abstract exercises, and all have unique solutions that can be reached using pure logic. They're difficult--and really satisfying exercise for your brain.