Sharpen your pencil and get ready to boost your brain with this brand-new numbers game. To solve each puzzle, fill the 16 cells with the numbers 1 to 16 using each number only once. Each puzzle has just one solution, and uses math you learned in grade school: addition, subtraction, multiplication, and division. The games, which all call for logic, imaginative thinking, intuitive elimination, and sheer persistence, are grouped in three categories, and range from relatively simple to super-challenging. The author's spirited instructions and sample puzzles walk you through the basics; clues for some puzzles provide what might be necessary encouragement. With 14 bonus puzzles aimed at children and those who want to start with the ultra-easy, these 150 puzzles will keep you thinking whether you're a student honing your math skills, a puzzle-lover looking for a challenge, or someone who just wants to get those brain synapses snapping!