Final answer:
The most commonly used envelope size for correspondence is #10, which is a standard business size. For weighing packages such as a box with 10 books and documents, Jesse should use grams or kilograms, which are the metric units for mass.
Step-by-step explanation:
The envelope size most commonly used for correspondence is #10. This is the standard business envelope size and is typically used for mailing documents such as letters and bills. The dimensions of a #10 envelope are 4 1/8 inches by 9 1/2 inches. Now, when considering Jesse's responsibility in the mailroom and having to choose the appropriate metric unit of mass for shipping a box that contains 10 books and some documents, Jesse should use grams or kilograms as these are the standard metric units for measuring weight. For smaller and lighter packages, grams might be sufficient, but for a box with multiple books, kilograms would likely be more appropriate.