22 pages of tough Sudoku for middle school and high school students. These 88 challenges give your students an opportunity to apply use logic and reasoning to problems. Each page has four six-by-six grids with 16, 18, 22 or 24 missing numbers (1, 2, 3, 4, 5 and 6) or letters (A, B, C, D, E and F). Each page has four levels of difficulty as students strategize in three directions (across rows, down columns and within rectangles) to find the missing numbers. If you are interested in developin