This One Minute Math Subtraction set includes a variety of subtraction problem sets. Each page has two half-sheet "tests' that are based on the same set of problems, but in a "shuffled" order. This helps prevent copying when two students next to each other are on the same set (Number - 8, 5 - a number, etc.). SOME SETS ARE INCREDIBLY SIMPLE, ALTERNATING BETWEEN TWO ANSWERS. I do not want you to be surprised as to what is included. I included problem sets in a logical order (Number - 0 up to