Set the clock. Every one of these puzzles is timed, to add to the difficulty...and to the fun and satisfaction of solving them. A children's version was so popular that now there's one for adults.

Get ready to work out the brain, because it's a race to the finish line as the minutes tick away on these timed puzzles. Even those who have a clue to the answers will find that the time limit makes everything deliciously challenging. Take a 50/50 shot at getting it right in quizzes that test your knowledge of trivia; there are only two choices to every question--but there are 20 questions and just three minutes to answer them. Match anagrams with their definitions: maybe the definition will help you unscramble the anagram, or maybe you'll have to figure out the letters first. Solvers get 10 minutes to complete four groups of 6 anagrams each. Or try the Brainstretchers, Letter Insertion, and Think Fast quizzes for some smart and speedy fun.