Discover the adventure and excitement of mathematical puzzles. Match your wits with the human computer. Sharpen your intellect, delight your friends and enjoy h

Math books for kids ages 9+ Help your 4th grade, 5th grade, middle school, or high school child build proficiency in math with the activity-packed Mark Twain Ma

300 Crossword Puzzles puts your trivia knowledge to the text with 300 fun-filled crossword puzzles that will keep you on your toes for hours at a time.

While many think of algorithms as specific to computer science, at its core algorithmic thinking is defined by the use of analytical logic to solve problems. Th