After over 20 years, 7 days a week of researching on creating of math, chess, and puzzles workbooks, Ho Math Chess has made a revolutionary innovation in creating math worksheets. This long, tremendous, and practical teaching experience have helped us develop and create this series of Ultimate Math Contest Preparation, Problem Solving, and Math IQ Puzzles workbooks.Ho Math Chess worksheets not only will raise students' marks; our worksheets also improve...