The document discusses shortcuts for adding long columns of numbers. It recommends beginning by looking for combinations of 10 that can be added together, such as 1 + 9, 5 + 5, and 8 + 2. These combinations of 10 should be added first before adding any remaining single-digit numbers. When a number repeats, such as adding multiple columns of the same number, multiplication can be used instead of repeatedly adding the number.